ANTI-LOCK BRAKE SYSTEM

1993 Jeep Cherokee

1993 BRAKES

Chrysler Corp. Anti-Lock - Teves

Jeep; Cherokee, Grand Cherokee, Grand Wagoneer, Wrangler DESCRIPTION

The Teves Mark IV Anti-Lock Brake System (ABS) consists of acceleration switch, Controller Anti-Lock Brake (CAB), ANTI-LOCK warning light, Hydraulic Control Unit (HCU), main relay, master cylinder, pedal travel sensor, pump motor relay, pump motor sensor, vacuum booster, 4 wheel speed sensors and axle shaft tone (pulse) rings.

During ABS operation, front wheels are controlled

individually and rear wheels are controlled together. ABS modulates brake fluid pressure during high pedal pressure and high vehicle deceleration to prevent wheel lock-up.

NOTE: For more information on brake system, see BRAKE SYSTEM article in this section.

OPERATION

The Teves Mark IV Anti-Lock Brake System (ABS) is activated during hard braking to prevent wheel lock-up. Wheel lock-up does not mean wheel has stopped, but wheel is turning slower than vehicle speed. When ignition is on, before vehicle is moved, Controller Anti-Lock Brake (CAB) performs a static system initialization. When vehicle speed reaches approximately 6 MPH, CAB briefly cycles pump to verify operation. Hydraulic Control Unit (HCU) solenoids are checked continuously.

When ABS is activated, vibrations and pulsations may be felt in brake pedal and solenoid valves clicking and pump motor running may be heard. Some wheel slip is required for best braking performance. This wheel slip may be heard as tire chirping. Do not confuse tire chirping with tire skidding. When vehicle is braked heavily, wheels will lock-up below 3 MPH. When braking on rough road surfaces, ABS may activate, detecting wheel lock-up tendencies from wheel hop.

CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in GENERAL INFORMATION.

BLEEDING BRAKE SYSTEM

NOTE: Use only DOT 3 brake fluid from a sealed container. DO NOT use DOT 5 silicone brake fluid.

  1. Ensure ignition is off. Clean master cylinder reservoir
    cover and surrounding area. Ensure reservoir is full. Bleeding
    sequence is master cylinder, Hydraulic Control Unit (HCU) valve body
    (at fluid lines), right rear wheel, left rear wheel, right front wheel
    and left front wheel
    .

  2. After bleeding master cylinder, position shop towel below
    4 hydraulic control unit brakelines. Using flare wrench, slightly open
    hydraulic control unit brakeline fittings individually.

  3. DO NOT allow brake fluid to contact paint or electrical
    connectors. Slowly depress brake pedal. Close hydraulic control unit
    brake pipe fitting and release brake pedal. Repeat process until no

air escapes from brake pipe fitting. Repeat procedure for remaining 3 brakelines.

4) Ensure master cylinder reservoir is full. Raise and
support vehicle. Bleed all 4 wheel calipers. Attach a clear hose to
right rear caliper bleeder valve and submerge other end of hose in
container of brake fluid.

NOTE: DO NOT pump brake pedal while bleeding brakes. Pumping brake pedal compresses air into tiny bubbles throughout system making bleeding more difficult.

  1. Open bleeder valve. Slowly depress brake pedal. Close
    bleeder valve and release brake pedal. Wait 5 seconds. Repeat process
    until no air bubbles are seen from hose. Tap lightly on
    cylinder/caliper housing to free trapped air. Close bleeder valve.
    Repeat process until no air bubbles are seen from hose. Repeat
    procedure on left rear, right front and left front bleeder valves.
    Ensure reservoir is full.

  2. Using DRB-II, follow prompts and perform BLEED BRAKES
    procedure. After performing BLEED BRAKES procedure using DRB-II,
    repeat steps 1)-5)
    . Ensure master cylinder reservoir is full.

ADJUSTMENTS

REAR WHEEL SPEED SENSOR

See REAR WHEEL SPEED SENSOR under REMOVAL & INSTALLATION.

REMOVAL & INSTALLATION

ABS MAIN SYSTEM RELAY

Removal & Installation

ABS main system relay is located on right side of engine compartment in Power Distribution Center (PDC). Turn ignition off. Remove cover from PDC. Locate and remove ABS main system relay from PDC. See Fig. 1. To install, reverse removal procedure.

92E22G3G

Fig. 1: Locating ABS System Relays Courtesy of Chrysler Corp.

ABS PUMP/MOTOR RELAY

Removal & Installation

ABS pump/motor relay is located on right side of engine compartment in Power Distribution Center (PDC). Turn ignition off. Remove cover from PDC. Locate and remove ABS pump/motor relay from PDC. See Fig. 1. To install, reverse removal procedure.

CONTROLLER ANTI-LOCK BRAKE (CAB)

Removal & Installation (Cherokee)

Turn ignition off. CAB is located under instrument panel to right of steering column. Remove screws attaching CAB mounting bracket to vehicle. Disconnect CAB electrical connector. Disconnect security alarm module electrical connector. Security alarm module is mounted on opposite side of mounting bracket. Remove CAB and mounting bracket. See Fig. 2. To install, reverse removal procedure. If installing a new CAB, transfer mounting bracket to new CAB.

Fig. 2: Locating Controller Anti-Lock Brake (CAB) Courtesy of Chrysler Corp.

CAUTION: DO NOT force CAB electrical connector onto CAB. CAB pins are easily damaged.

Removal & Installation (Grand Cherokee & Grand Wagoneer) Turn ignition off. Disconnect negative battery cable. CAB is located on driver-side inner fender panel. Remove screws attaching CAB to fender panel bracket. Remove CAB from bracket for access to CAB electrical connector. Release strap securing harness connector to CAB. Tilt CAB electrical connector upward to disengage. Slide CAB electrical connector from retaining tangs. Remove CAB from vehicle. To install, reverse removal procedure.

Removal & Installation (Wrangler)

  1. Turn ignition off. Disconnect negative battery cable. CAB
    is located above heater/air conditioning plenum housing in line with
    the glove box. Remove bolts and nuts securing CAB to dash panel. Bolts
    and nuts are accessible from the engine compartment and are located to
    the right of the battery.

  2. On models with air conditioning, remove air conditioning
    fascia panel and ducts to access CAB harness connector. Release strap
    securing harness connector to CAB. Tilt CAB electrical connector
    outward to disengage. Slide CAB electrical connector from retaining
    tangs. Remove CAB from vehicle. To install, reverse removal procedure.

FRONT WHEEL SPEED SENSOR

Removal & Installation

  1. Turn ignition off. Raise and support vehicle. Remove wheel
    and tire assembly. Clean area surrounding wheel speed sensor prior to
    removal. Remove bolt attaching wheel speed sensor to steering knuckle.

  2. Unseat grommet retaining wheel speed sensor wire in wheel
    well panel. Disconnect wheel speed sensor electrical connector in
    engine compartment. Disconnect wheel speed sensor wire harness from
    clips on body, chassis, and steering knuckle. Remove wheel speed
    sensor from vehicle.

  3. To install, reverse removal procedure. Remove all kinks
    and twists from wheel speed sensor wire harness. Ensure wheel speed
    sensor wire harness is installed in clips on body, chassis and
    steering knuckle. Use Loctite on wheel speed sensor mounting bolt.

  4. Tighten wheel speed sensor bolt to specification. See
    TORQUE SPECIFICATIONS table. Air gap is not adjustable. Air gap should
    be .040" (1.3 mm). If air gap is not to specification, replacement of
    wheel speed sensor and/or tone wheel may be necessary.

"G" SWITCH

Removal & Installation (Except Wrangler)

Turn ignition off. Disconnect negative battery cable. Tilt rear seat assembly forward to access "G" switch. Disconnect "G" switch electrical connector. Remove "G" switch mounting bolts. Remove "G" switch. See Fig. 3. To install, reverse removal procedure. Ensure arrow on top of "G" switch is facing toward front of vehicle.

Fig. 3: Locating "G" Switch (Typical Except Wrangler) Courtesy of Chrysler Corp.

Removal & Installation (Wrangler)

Turn ignition off. Disconnect negative battery cable. Move driver’s seat assembly forward or rearward to access "G" switch. Disconnect "G" switch electrical connector. Remove "G" switch mounting bracket-to-floorpan screws. Remove "G" switch from mounting bracket. See Fig. 4. To install, reverse removal procedure. Ensure arrow on top of "G" switch is facing toward front of vehicle.

CCD Connector

"G- Switch


ition

Fig. 4: Locating "G" Switch & CCD Connector (Wrangler) Courtesy of Chrysler Corp.

HYDRAULIC CONTROL UNIT (HCU)

Removal & Installation

  1. Turn ignition off. Disconnect negative battery cable.
    Disconnect pedal travel sensor electrical connector. Remove air
    cleaner and hoses
    . On Grand Cherokee and Grand Wagoneer, remove
    windshield washer reservoir. On all models, position a small drain
    container under master cylinder reservoir hoses. Disconnect master
    cylinder reservoir hoses at HCU and drain fluid into container. See
    Fig. 5. Discard fluid. Disconnect HCU electrical connectors.

  2. On Grand Cherokee and Grand Wagoneer, remove combination
    valve. On all models, identify HCU brakelines for reassembly
    reference. Disconnect brakelines from HCU. Remove bolt and nuts
    attaching HCU mounting bracket to inner fender panel. Remove HCU from
    vehicle. To install, reverse removal procedure. Bleed brake system.
    See BLEEDING BRAKE SYSTEM.

Fig. 5: Locating Hydraulic Control Unit (HCU) Courtesy of Chrysler Corp.

PEDAL TRAVEL SENSOR

Removal & Installation

Turn ignition off. Disconnect pedal travel sensor electrical connector. Pump brake pedal to exhaust all vacuum from vacuum booster. Unseat pedal travel sensor retaining ring. Remove pedal travel sensor from vacuum booster. See Fig. 6. To install, reverse removal procedure. Ensure color dot on face of vacuum booster matches color of plunger tip. If colors are different, replace plunger tip to match color dot on vacuum booster.

Fig. 6: Locating Pedal Travel Sensor Courtesy of Chrysler Corp.

REAR WHEEL SPEED SENSOR

Removal

  1. Turn ignition off. Raise and fold rear seat to access rear
    wheel speed sensor connectors. Disconnect rear wheel speed sensor
    electrical connector. Push rear wheel speed sensor grommet and wire
    harness through floorpan on vehicle.

  2. Raise and support vehicle. Remove wheel and brake drum.
    Remove clips attaching rear wheel speed sensor wire harness to
    brakelines. Unseat rear wheel speed sensor grommet from brake backing
    plate. Remove rear wheel speed sensor mounting bolt. Push rear wheel
    speed sensor through grommet opening in backing plate. Remove rear
    wheel speed sensor from vehicle.

Installation

  1. If original wheel speed sensor is being installed, go to
    step 3). If a NEW wheel speed sensor is being installed, position
    wheel speed sensor until cardboard spacer contacts tone wheel.

  2. Use Loctite on the wheel speed sensor mounting bolt.
    Tighten wheel speed sensor mounting bolt to specification. Refer to

TORQUE SPECIFICATIONS. Spin rear axle by hand until cardboard spacer is peeled from sensor face. Air gap adjustment should be correct. Using a brass feeler gauge, check air gap adjustment. Air gap should be .043" (1.1 mm). If air gap is not correct, adjust as necessary. Go to step 4).

  1. Remove any remaining pieces of cardboard from sensor face.
    Install wheel speed sensor. Using a brass feeler gauge, adjust air
    gap. Air gap should be
    .043" (1.1 mm). Use Loctite on wheel speed
    sensor mounting bolt. Tighten wheel speed sensor mounting bolt to
    specification. See TORQUE SPECIFICATIONS.

  2. Remove all kinks and twists from wheel speed sensor wire
    harness. Ensure wheel speed sensor wire harness is installed in clips
    on brakelines
    . To complete installation, reverse removal procedure.

DIAGNOSIS & TESTING

NOTE: DRB-II and appropriate cartridge are necessary for

diagnosing ABS.

WARNING LIGHTS

Amber ABS Warning Light

After engine start-up, ABS warning light glows as part of a self-check feature. ABS warning light normally will light for 2-3 seconds and then go out. If ABS warning light remains illuminated after engine start-up, diagnosis will be necessary to determine which component or circuit is malfunctioning.

Red BRAKE Warning Light

With ignition on, Red BRAKE warning light will glow when low brake fluid level is detected or parking brake switch is closed. BRAKE warning light normally indicates a hydraulic or mechanical failure is present.

PRE-DIAGNOSTIC INSPECTION

  1. Check master cylinder reservoir for correct fluid level.
    Inspect Hydraulic Control Unit (HCU) for leakage and wiring damage.
    Check caliper piston for activation and release. Check all brakes to
    verify no drag exists.

  2. Check speed sensors for correct mounting and alignment.
    Inspect wire harness for correct routing. Ensure connectors are not
    damaged and have good contact.

  3. Verify all wheel bearings are not worn or causing wheel
    wobble. Ensure all tires are in good condition and properly inflated.
    After performing pre-diagnostic inspection, perform TEST-1A under
    SELF-DIAGNOSTIC TESTS using DRB-II. See Figs. 4, 7 and 8.

T

CCD Connector Location

92B22G41

Fig. 7: Locating CCD Connector (Cherokee) Courtesy of Chrysler Corp.

Fig. 8: Locating CCD Connector (Grand Cherokee & Grand Wagoneer) Courtesy of Chrysler Corp.

INTERMITTENTS

Most intermittent problems are caused by faulty electrical

connections or wiring; however, a sticking relay or solenoid can cause
a failure.

When intermittent failure is encountered, check for fault

messages stored in CAB. If fault messages are found, inspect related

components and circuitry for poor connections. If no trouble codes are
found, inspect suspect circuits as follows:

  1. Check for poor mating of connector halves, or terminals not
    fully seated in connector body (backed-out)
    .

  2. Check for improperly formed or damaged terminals. Carefully
    reform all connector terminals of problem circuit to increase
    contact tension.

  3. Check for poor terminal-to-wire connection.

  4. Check for hydraulic system leaks.

CLEARING FAULT MESSAGES

DRB-II

Using DRB-II, select ADJUSTMENTS. Press "1" (ERASE FAULTS key). Press ENTER key. DRB-II will display ERASE FAULTS ARE YOU SURE? (ENTER TO ERASE). Press ENTER key. DRB-II will display ERASE FAULTS TURN KEY OFF. Turn ignition off. Turn ignition on. DRB-II will display

ERASE FAULTS FAULTS ERASED. Faults are now erased.

Ignition Cycle Default

If no fault codes occur for 50 driving cycles, any existing fault messages will be cleared from CAB memory. A drive cycle occurs when ignition is turned on and vehicle is driven faster than 10 MPH.

CONNECTOR IDENTIFICATION

CONNECTOR IDENTIFICATION DIRECTORY TABLE

Connector

Figure

ABS Disconnect Connector 9

ABS Main System Relay Socket Connector 10

ABS Pump/Motor Relay Socket Connector 11

Controller Anti-Lock Brake (CAB) Connector 12

"G" Switch Connector 13

Hydraulic Control Unit (HCU) Connector 14

Pump/Motor Connector 15

Fig. 9: Identifying ABS Disconnect Connector Terminals Courtesy of Chrysler Corp.



Fig. 10: Identifying ABS Main System Relay Connector Terminals Courtesy of Chrysler Corp.

92F22G45

Fig. 11: Identifying ABS Pump/Motor Relay Connector Terminals Courtesy of Chrysler Corp.


92G22G4G



Fig. 12: Controller Anti-Lock Brake (CAB) Connector Terminal ID Courtesy of Chrysler Corp.

Fig. 13: Identifying "G" Switch Connector Terminals Courtesy of Chrysler Corp.

92 122648

Fig. 14: Hydraulic Control Unit (HCU) Connector Terminal ID Courtesy of Chrysler Corp.

92J22G49

Fig. 15: Identifying Pump/Motor Connector Terminals Courtesy of Chrysler Corp.

SELF-DIAGNOSTIC TESTS

NOTE: Connector and terminal identification illustrations in following tests are provided courtesy of Chrysler Corp.

NOTE: For connector terminal identification in following tests,

see CONNECTOR IDENTIFICATION under DIAGNOSIS & TESTING. For wire color and terminal identification, see WIRING DIAGRAMS.

TEST 1A

READING FAULT MESSAGES

Using DRB-II, read fault messages and perform appropriate test listed in FAULT MESSAGES table. If DRB-II displays NO RESPONSE message, perform TEST 23A. If other DRB-II related communication problems exist, see VEHICLE COMMUNICATIONS article in ENGINE PERFORMANCE. If multiple fault messages are present, fault repairs must be performed in order in which they are displayed. If no fault messages are present, perform VERIFICATION TEST VER-1A.

FAULT MESSAGES TABLE

Fault Message Perform Test

CONTROLLER FAILURE 2A

"G" SWITCH NOT PROCESSABLE 3A

HYDRAULIC FAILURE 4A

LEFT FRONT INLET VALVE 5A

LEFT FRONT OUTLET VALVE 6A

LEFT FRONT SENSOR CIRCUIT FAILURE 7A

LEFT FRONT SENSOR CONTINUITYK25 MPH 7A

LEFT FRONT SENSOR CONTINUITYJ25 MPH 7A

LEFT FRONT SENSOR SIGNAL MISSING 7A

LEFT FRONT WHEEL SPEED COMPARISON 7A

REAR INLET VALVE 9A

REAR OUTLET VALVE 10A

LEFT REAR SENSOR CIRCUIT FAILURE 11A

LEFT REAR SENSOR CONTINUITYK25 MPH 11A

LEFT REAR SENSOR CONTINUITYJ25 MPH 11A

LEFT REAR SENSOR SIGNAL MISSING 11A

LEFT REAR WHEEL SPEED COMPARISON 11A

MAIN RELAY/POWER CIRCUIT FAILURE 13A

PEDAL TRAVEL SENSOR CIRCUIT 14A

PUMP MOTOR CIRCUIT NOT WORKING PROPERLY 15A

RIGHT FRONT INLET VALVE 16A

RIGHT FRONT OUTLET VALVE 17A

RIGHT FRONT CIRCUIT FAILURE 18A

RIGHT FRONT SENSOR CONTINUITYK25 MPH 18A

RIGHT FRONT SENSOR CONTINUITYJ25 MPH 18A

RIGHT FRONT REAR SENSOR SIGNAL MISSING 18A

RIGHT FRONT WHEEL SPEED COMPARISON 18A

RIGHT REAR SENSOR CIRCUIT FAILURE 20A

RIGHT REAR SENSOR CONTINUITYK25 MPH 20A

RIGHT REAR SENSOR CONTINUITYJ25 MPH 20A

RIGHT REAR SENSOR SIGNAL MISSING 20A

RIGHT REAR WHEEL SPEED COMPARISON 2 0A

ABS WARNING LAMP ILLUMINATION PROBLEM 22A

NO RESPONSE 23A

TEST 2A

CONTROLLER FAILURE

If DRB-II displays CONTROLLER FAILURE, replace Controller Anti-Lock Brake (CAB). Perform VERIFICATION TEST VER-1A.

TEST 3A

"G" SWITCH NOT PROCESSABLE

  1. Ensure "G" switch sensor assembly is properly installed.
    If not properly installed, repair as necessary and perform
    VERIFICATION TEST VER-1A. If "G" switch is properly installed, turn
    ignition off. Disconnect and inspect CAB 55-pin connector and "G"
    switch sensor 3-pin connector. Repair connectors as necessary.

  2. Turn ignition on. With DRB-II in voltmeter mode, probe "G"
    switch connector terminals individually. If voltage is present, repair
    short to voltage in that "G" switch circuit. Perform VERIFICATION TEST
    VER-1A. If voltage is not present at any terminals, go to next step.

  3. Turn ignition off. With DRB-II in ohmmeter mode, probe "G"
    switch connector terminals individually with remaining lead connected
    to chassis ground. If resistance at any terminal is less than
    5 ohms,
    repair short to ground in that circuit. Perform VERIFICATION TEST VER-
    1A.

  4. If resistance at each terminal is more than 5 ohms,
    connect jumper wire between ground and "G" switch terminals No. 1-3.
    Check for continuity to ground on CAB terminals No. 25, 26 and 43. If
    continuity to ground does not exist, repair open in that circuit.
    Perform VERIFICATION TEST VER-1A. If continuity to ground exists,
    replace CAB. Perform VERIFICATION TEST VER-1A.

TEST 4A

HYDRAULIC FAILURE

  1. Inspect brake system for hydraulic leaks, and repair as
    necessary. If brake system is okay, using DRB-II, read fault messages.
    If DRB-II displays PUMP/MOTOR NOT WORKING PROPERLY, perform TEST 15A.
    If DRB-II displays PEDAL TRAVEL SENSOR CIRCUIT, perform TEST 14A. If
    DRB-II does not display PUMP/MOTOR NOT WORKING PROPERLY or PEDAL
    TRAVEL SENSOR CIRCUIT, using DRB-II, erase fault messages.

  2. Using DRB-II, monitor read faults display for 4 minutes.
    If any fault messages are displayed, perform TEST 1A. If no fault
    messages are displayed, depress brake pedal and hold down until
    instructed to release it. Using DRB-II, actuate hydraulic valve test.
    Release brake pedal.

  3. If brake pedal came back up, perform TEST 14A. If brake
    pedal dropped all the way to the floor or there were not
    3 slight
    drops in the brake pedal, perform TEST 4B. If the brake pedal did not
    come back up at end of test, replace pump/motor assembly. If the brake
    pedal did come back up at end of test, replace CAB. If CAB has already
    been replaced, replace HCU. Perform VERIFICATION TEST VER-1A.

TEST 4B

HYDRAULIC FAILURE

Disconnect and inspect CAB 55-pin connector. Repair connector as necessary. Disconnect and inspect hydraulic unit 10-pin connector. Repair connector as necessary. If terminals of both connectors are not

pushed out, damaged or improperly wired, replace hydraulic control unit. Perform VERIFICATION TEST VER-1A.

TEST 5A

LEFT FRONT INLET VALVE

  1. Disconnect and inspect hydraulic unit 10-pin connector.
    Repair connector as necessary. Turn ignition on. With DRB-II in
    voltmeter mode, probe terminal No.
    4 (White/Light Green wire) of
    hydraulic unit connector. If voltage is present, repair short to
    voltage in White/Light Green wire. Perform VERIFICATION TEST VER-1A.

  2. If voltage is not present, turn ignition off. Disconnect
    and inspect CAB 55-pin connector. Repair connector as necessary. With
    DRB-II in ohmmeter mode, probe terminal No. 4 (White/Light Green wire)
    of hydraulic unit connector. If resistance is less than
    5 ohms, repair
    short to ground in White/Light Green wire.

  3. If resistance is more than 5 ohms, check resistance of
    White/Light Green wire between terminals No. 20 of CAB connector and
    No. 4 of hydraulic unit connector using an external ohmmeter. If
    resistance is more than 5 ohms, repair open in White/Light Green wire.
    Perform VERIFICATION TEST VER-1A.

  4. If resistance is less than 5 ohms, measure resistance of
    left front inlet valve. If resistance is 5-8 ohms, replace CAB.
    Perform VERIFICATION TEST VER-1A. If resistance is not
    5-8 ohms,
    replace hydraulic control unit. Perform VERIFICATION TEST VER-1A.

TEST 6A

LEFT FRONT OUTLET VALVE

  1. Disconnect and inspect hydraulic unit 10-pin connector.
    Repair connector as necessary. Turn ignition on. With DRB-II in
    voltmeter mode, probe terminal No.
    9 (Dark Green/Black wire) of
    hydraulic unit connector. If voltage is present, repair short to
    voltage in Dark Green/Black wire. Perform VERIFICATION TEST VER-1A.

  2. If voltage is not present, turn ignition off. Disconnect
    and inspect CAB 55-pin connector. Repair connector as necessary. With
    DRB-II in ohmmeter mode, probe terminal No.
    9 (Dark Green/Black wire)
    of hydraulic unit connector. If resistance is less than 5 ohms, repair
    short to ground in Dark Green/Black wire.

  3. If resistance is more than 5 ohms, check resistance of
    Dark Green/Black wire between terminals No. 2 of CAB connector and No.
    9 of hydraulic unit connector using an external ohmmeter. If
    resistance is more than
    5 ohms, repair open in Dark Green/Black wire.
    Perform VERIFICATION TEST VER-1A.

  4. If resistance is less than 5 ohms, measure resistance of
    left front outlet valve. If resistance is not
    3-5 ohms, replace
    hydraulic control unit. Perform VERIFICATION TEST VER-1A. If
    resistance is 3-5 ohms, replace CAB. Perform VERIFICATION TEST VER-1A.

TEST 7A

LEFT FRONT SENSOR CIRCUIT FAILURE

1) Using DRB-II, read and record all speed sensor fault messages. If DRB-II does not display LEFT FRONT SENSOR CIRCUIT FAILURE, perform TEST 8A. If DRB-II displays LEFT FRONT SENSOR CIRCUIT FAILURE, inspect left front wheel speed sensor for damage. If sensor is damaged, repair or replace sensor as necessary. Perform

VERIFICATION TEST VER-1A. If sensor is okay, turn ignition off.

  1. Disconnect and inspect CAB 55-pin connector. Repair
    connector as necessary. Turn ignition on. With DRB-II in voltmeter
    mode, probe terminal No. 48 (Red wire) of CAB connector. If voltage is
    present, repair short to battery in Red wire. Perform VERIFICATION
    TEST VER-1A.

  2. If voltage is not present, turn ignition off. With DRB-II
    in ohmmeter mode, probe terminal No.
    48 (Red wire) of CAB connector.
    If resistance is less than 5 ohms, repair short to ground in Red wire.
    Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms,
    go to next step.

  3. Using an external ohmmeter, check resistance between
    terminal No. 48 (Red wire) and No. 30 (Red/Dark Blue wire) of CAB
    connector. If resistance is 900-1300 ohms, replace CAB. Perform
    VERIFICATION TEST VER-1A. If resistance is not
    900-1300 ohms,
    disconnect and inspect left front wheel speed sensor connector.

  4. Using an external ohmmeter, check resistance between left
    wheel speed sensor connector terminals. If resistance is not
    900-1300
    ohms, replace wheel speed sensor. Perform VERIFICATION TEST VER-1A. If
    resistance is 900-1300 ohms, check resistance of Red wire between
    terminal No.
    48 of CAB connector and No. 1 of left front wheel speed
    sensor connector using an external ohmmeter.

  5. If resistance is more than 5 ohms, repair open Red wire.
    Perform VERIFICATION TEST VER-1A. If resistance is less than
    5 ohms,
    repair open Red/Dark Blue wire. Perform VERIFICATION TEST VER-1A.

TEST 8A

LEFT FRONT SENSOR

  1. Inspect left front wheel speed sensor for damage. Repair
    or replace sensor as necessary. Perform VERIFICATION TEST VER-1A. If
    sensor is okay, check left front sensor tone (pulse) ring for damage.
    Repair or replace tone ring as necessary. Perform VERIFICATION TEST
    VER-1A. If tone ring is okay, inspect left front wheel speed sensor
    wiring harness for damage.

  2. Repair or replace wiring as necessary. Perform

VERIFICATION TEST VER-1A. If wiring harness is okay, disconnect and inspect left front wheel speed sensor connector. Repair connector as necessary. Using an external ohmmeter, check resistance between left front wheel speed sensor connector terminals.

3) If resistance is not 900-1300 ohms, replace wheel speed
sensor. Perform VERIFICATION TEST VER-1A. If resistance is
900-1300
ohms, replace CAB. Perform VERIFICATION TEST VER-1A.

NOTE: If excessive axle deflection occurs on extremely bumpy

surfaces or during off road use, it is possible for a wheel speed sensor to set a code.

TEST 9A

REAR INLET VALVE

  1. Disconnect and inspect hydraulic unit 10-pin connector.
    Repair connector as necessary. Turn ignition on. With DRB-II in
    voltmeter mode, probe terminal No.
    4 (White/Black wire on Cherokee and
    Wrangler or White/Red wire on Grand Cherokee and Grand Wagoneer) of
    hydraulic unit connector. If voltage is present, repair short to
    voltage in White/Black or White/Red wire. Perform VERIFICATION TEST
    VER-1A.

  2. If voltage is not present, turn ignition off. Disconnect

and inspect CAB 55-pin connector. Repair connector as necessary. With DRB-II in ohmmeter mode, probe terminal No. 4 of hydraulic unit connector. If resistance is less than 5 ohms, repair short to ground in White/Black or White/Red wire. Perform VERIFICATION TEST VER-1A.

  1. If resistance is less than 5 ohms, check resistance of
    between terminal No. 54 of CAB connector and No. 4 of hydraulic unit
    connector using an external ohmmeter. If resistance is more than 5
    ohms, repair open in White/Black or White/Red wire. Perform
    VERIFICATION TEST VER-1A.

  2. Using an external ohmmeter, check resistance between
    terminals No. 4 and 5 of hydraulic control unit pigtail connector. If
    resistance is not 5-8 ohms, replace hydraulic control unit. Perform
    VERIFICATION TEST VER-1A. If resistance is 5-8 ohms, replace CAB.
    Perform VERIFICATION TEST VER-1A.

TEST10A

REAR OUTLET VALVE

  1. Disconnect and inspect hydraulic unit 10-pin connector.
    Repair connector as necessary. Turn ignition on. With DRB-II in
    voltmeter mode, probe terminal No.
    7 (Dark Green/Orange wire) of
    hydraulic unit connector. If voltage is present, repair short to
    voltage in Dark Green/Orange wire. Perform VERIFICATION TEST VER-1A.

  2. If voltage is not present, turn ignition off. Disconnect
    and inspect CAB 55-pin connector. Repair connector as necessary. With
    DRB-II in ohmmeter mode, probe terminal No. 7 (Dark Green/Orange wire)
    of hydraulic unit connector. If resistance is less than
    5 ohms, repair
    short to ground in Dark Green/Orange wire.

  3. If resistance is more than 5 ohms, check resistance of
    Dark Green/Orange wire between terminal No.
    36 of CAB connector and
    No.
    7 of hydraulic unit connector using an external ohmmeter. If
    resistance is more than 5 ohms, repair open Dark Green/Orange wire.
    Perform VERIFICATION TEST VER-1A. If resistance is less than 5 ohms,
    go to next step.

  4. Using an external ohmmeter, check resistance between
    terminals No.
    7 and 10 of hydraulic control unit connector. If
    resistance is not 3-5 ohms, replace hydraulic control unit. Perform
    VERIFICATION TEST VER-1A. If resistance is
    3-5 ohms, replace CAB.
    Perform VERIFICATION TEST VER-1A.

TEST 11A

LEFT REAR SENSOR CIRCUIT FAILURE

1) Using DRB-II, read and record all speed sensor fault

messages. If DRB-II does not display LEFT REAR SENSOR CIRCUIT FAILURE, perform TEST 12A. If DRB-II displays LEFT REAR SENSOR CIRCUIT FAILURE, inspect left rear wheel speed sensor for damage. If sensor is damaged, repair or replace sensor as necessary. Perform VERIFICATION TEST VER-1A. If sensor is okay, turn ignition off.

  1. Disconnect and inspect CAB 55-pin connector. Repair
    connector as necessary. Turn ignition on. With DRB-II in voltmeter
    mode, probe terminal No. 46 (Light Green wire) of CAB connector. If
    voltage is present, perform TEST 11B.

  2. If voltage is not present, turn ignition off. With DRB-II
    in ohmmeter mode, probe terminal No. 46 (Light Green wire) of CAB
    connector. If resistance is less than
    5 ohms, perform TEST 11C. If
    resistance is more than
    5 ohms, using an external ohmmeter, check
    resistance between terminal No. 46 (Light Green wire) and No. 28
    (Light Green/Dark Blue wire) of CAB connector.

  3. If resistance is 900-1300 ohms, replace CAB. Perform
    VERIFICATION TEST VER-1A. If resistance is not 900-1300 ohms,
    disconnect and inspect left rear wheel speed sensor connector. Using
    an external ohmmeter, check resistance between left rear wheel speed
    sensor connector terminals. If resistance is not
    900-1300 ohms,
    replace wheel speed sensor. Perform VERIFICATION TEST VER-1A.

  4. If resistance is 900-1300 ohms, connect a jumper wire
    between terminal No. 46 (Light Green wire) of CAB connector and
    ground. With DRB-II in ohmmeter mode, probe Light Green wire of left
    rear wheel speed sensor connector. If resistance is more than 5 ohms,
    perform TEST 11D. If resistance is less than 5 ohms, perform TEST 11E.

TEST11B

LEFT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee and Wrangler, repair short to battery voltage
    in Light Green wire. Perform VERIFICATION TEST VER-1A. On Grand
    Cherokee and Grand Wagoneer, disconnect and inspect Black ABS 8-pin
    disconnect connector. Connector is located behind left side kick
    panel. Repair connector as necessary. With DRB-II in voltmeter mode,
    probe Light Green wire of ABS disconnect connector.

  2. If voltage is not present, repair short to battery voltage
    in Light Green wire between wheel speed sensor and CAB disconnect
    connector. Perform VERIFICATION TEST VER-1A. If voltage is present,
    repair short to battery voltage in Light Green wire between ABS
    disconnect connector and CAB 55-pin connector. Perform VERIFICATION
    TEST VER-1A.

TEST 11C

LEFT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee and Wrangler, repair short to ground in Light
    Green wire. Perform VERIFICATION TEST VER-1A. On Grand Cherokee and
    Grand Wagoneer, disconnect and inspect Black CAB 8-pin disconnect
    connector. Connector is located behind left side kick panel. Repair
    connector as necessary. With DRB-II in ohmmeter mode, probe Light
    Green wire of ABS disconnect connector.

  2. If resistance is more than 5 ohms, repair short to ground
    in Light Green wire between wheel speed sensor and ABS disconnect
    connector. Perform VERIFICATION TEST VER-1A. If resistance is less
    than
    5 ohms, repair short to ground in Light Green wire between ABS
    disconnect connector and CAB 55-pin connector. Perform VERIFICATION
    TEST VER-1A.

TEST11D

LEFT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee and Wrangler, repair open in Light Green wire.
    Perform VERIFICATION TEST VER-1A. On Grand Cherokee and Grand
    Wagoneer, disconnect and inspect Black CAB 8-pin disconnect connector.
    Connector is located behind left side kick panel. Repair connector as
    necessary. With DRB-II in ohmmeter mode, probe Light Green wire of ABS
    disconnect connector.

  2. If resistance is less than 5 ohms, repair open in Light
    Green wire between wheel speed sensor and ABS disconnect connector.
    Perform VERIFICATION TEST VER-1A. If resistance is more than
    5 ohms,
    repair open in Light Green wire between ABS disconnect connector and

CAB 55-pin connector. Perform VERIFICATION TEST VER-1A.

TEST11E

LEFT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee and Wrangler, repair open in Light Green/Dark
    Blue wire. Perform VERIFICATION TEST VER-1A. On Grand Cherokee and
    Grand Wagoneer, disconnect and inspect Black ABS 8-pin disconnect
    connector. Connector is located behind left side kick panel. Repair
    connector as necessary. Connect a jumper wire between terminal No. 28
    (Light Green/Dark Blue wire) of CAB connector and ground. With DRB-II
    in ohmmeter mode, probe Light Green/Dark Blue wire of ABS disconnect
    connector.

  2. If resistance is less than 5 ohms, repair open in Light
    Green/Dark Blue wire between wheel speed sensor and ABS disconnect
    connector. Perform VERIFICATION TEST VER-1A. If resistance is more
    than
    5 ohms, repair open in Light Green/Dark Blue wire between ABS
    disconnect connector and CAB 55-pin connector. Perform VERIFICATION
    TEST VER-1A.

TEST12A

LEFT REAR SENSOR

  1. Inspect left rear wheel speed sensor. If speed sensor is
    damaged, contaminated or loose, repair or replace speed sensor as
    necessary. Perform VERIFICATION TEST VER-1A. If speed sensor is okay,
    inspect left rear tone (pulse) ring for damaged teeth or excessive
    runout. Runout should not exceed
    .003" (.08 mm). Repair or replace
    tone ring as necessary. Perform VERIFICATION TEST VER-1A.

  2. If tone ring is okay, using a feeler gauge, check left
    rear wheel sensor-to-tone ring clearance. If clearance is not
    .036-.
    050" (.91-1.27 mm), repair as necessary. If clearance is .036-.050" (.
    91-1.27 mm), inspect left rear wheel speed sensor inspect left front
    wheel speed sensor wiring harness for damage.

  3. Repair or replace wiring as necessary. If wiring harness
    is okay, disconnect and inspect left rear wheel speed sensor
    connector. Repair connector as necessary. Using an external ohmmeter,
    check resistance between left rear wheel speed sensor connector
    terminals.

  4. If resistance is not 900-1300 ohms, replace wheel speed
    sensor. Perform VERIFICATION TEST VER-1A. If resistance is
    900-1300
    ohms, replace CAB. Perform VERIFICATION TEST VER-1A.

NOTE: If excessive axle deflection occurs on extremely bumpy

surfaces or during off road use, it is possible for a wheel speed sensor to set a code.

TEST 13A

MAIN RELAY/POWER CIRCUIT FAILURE

  1. Check ABS system fuse in Power Distribution Center (PDC).
    If fuse is not okay, perform TEST 13B. If fuse is okay, go to next
    step.

  2. Check if charging system is overcharging. If charging
    system is operating properly, go to next step. If charging system is
    not operating properly, repair as necessary. Perform VERIFICATION TEST
    VER-1A.

  3. Temporarily replace ABS main relay with another 5-terminal
    relay from PDC. Using DRB-II, erase ABS fault messages. Cycle ignition
    off and on. Using DRB-II, read ABS fault messages. If MAIN RELAY/POWER
    CIRCUIT FAILURE message is displayed, go to next step. If fault is not
    displayed, replace ABS main relay. Perform VERIFICATION TEST VER-1A.

  4. Install replacement 5-terminal relay back into PDC,
    leaving ABS main relay disconnected (removed). With DRB-II in
    voltmeter mode, probe fused battery feed Red/Dark Green wire

(Red/Light Green wire on Grand Cherokee and Grand Wagoneer) at ABS main relay socket. If voltage is more than 9 volts, go to next step. If voltage is less than 9 volts, repair open Red/Dark Green wire

(Red/Light Green on Grand Cherokee and Grand Wagoneer) wire to ABS fuse in PDC. Perform VERIFICATION TEST VER-1A.

  1. Turn ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. Ensure ABS main relay is
    still disconnected. Using an external ohmmeter, check continuity of
    Pink (Pink/Dark Blue on Grand Cherokee and Grand Wagoneer) wire
    between CAB connector terminal No.
    34 and ABS main relay socket
    terminal "C". If resistance is less than 5 ohms, go to next step. If
    resistance is more than 5 ohms, repair open Pink (Pink/Dark Blue on
    Grand Cherokee and Grand Wagoneer) wire to ABS main relay. Perform
    VERIFICATION TEST VER-1A.

  2. Check continuity of Gray/Yellow wire between CAB connector
    terminal No. 3 and ABS main relay socket terminal "B". If resistance
    is less than
    5 ohms, go to next step. If resistance is more than 5
    ohms, repair open Gray/Yellow wire to ABS main relay. Perform
    VERIFICATION TEST VER-1A.

  3. Check continuity of Gray/Yellow wire between CAB connector
    terminal No. 33 and ABS main relay socket terminal "B". If resistance
    is less than 5 ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If
    resistance is more than 5 ohms, repair open Gray/Yellow wire to ABS
    main relay. Perform VERIFICATION TEST VER-1A.

TEST13B

MAIN RELAY/POWER CIRCUIT FAILURE

  1. Remove ABS system fuse from Power Distribution Center
    (PDC). Remove ABS main relay from PDC, and inspect connector. Repair
    connector as necessary. With DRB-II in ohmmeter mode, probe fused
    battery feed Red/Dark Green wire (Red/Light Green wire on Grand
    Cherokee and Grand Wagoneer or Red/Dark Blue wire on Wrangler) at ABS
    main relay socket. If resistance is less than
    5 ohms, repair Red/Dark
    Green wire (Red/Light Green wire on Grand Cherokee and Grand Wagoneer
    or Red/Dark Blue wire on Wrangler) for a short to ground. Perform
    VERIFICATION TEST VER-1A. If resistance is more than
    5 ohms, go to
    next step.

  2. Remove ABS pump/motor relay from PDC, and inspect

connector. Repair connector as necessary. Using an external ohmmeter, measure resistance of ABS pump/motor relay coil. See Fig. 16. If resistance is 35-65 ohms, go to next step. If resistance is not 35-65 ohms, replace ABS pump/motor relay. Perform VERIFICATION TEST VER-1A.

3) Disconnect hydraulic control unit 10-pin connector. With
DRB-II in ohmmeter mode, probe Gray/Yellow wire (Gray/Pink wire on
Grand Cherokee and Grand Wagoneer) at ABS main relay socket terminal
"B"
. If resistance is less than 5 ohms, repair Gray/Yellow wire
(Gray/Pink wire on Grand Cherokee and Grand Wagoneer) for a short to

ground. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, go to next step.

4) Reconnect all disconnected components. Install a new ABS
fuse in PDC and cycle ignition off and on. Inspect ABS fuse in PDC. If
fuse is okay (does not blow), perform TEST 13C. If fuse is not okay

(blows), replace hydraulic control unit. Perform VERIFICATION TEST VER-1A.

Fig. 16: Measuring ABS Pump/Motor Relay Resistance

TEST13C

MAIN RELAY/POWER CIRCUIT FAILURE

  1. Ensure DRB-II is NOT in TEVES ABS DIAGNOSTIC MODE. Road
    test vehicle, making several ABS stops. Inspect ABS fuse in PDC. If
    fuse is okay (does not blow), ABS system is operating properly at this
    time. Perform VERIFICATION TEST VER-1A.

  2. If fuse is not okay (blows), inspect ABS wiring harness
    for damage and repair as necessary. Perform VERIFICATION TEST VER-1A.
    If wiring harness is okay, replace hydraulic control unit. Perform
    VERIFICATION TEST VER-1A.

TEST14A

PEDAL TRAVEL SENSOR CIRCUIT

  1. Inspect pedal travel sensor connector. Sensor is located
    on right side of brake booster. If connector is disconnected and/or
    damaged, repair connector as necessary and perform VERIFICATION TEST
    VER-1A. If connector is properly connected and NOT damaged, go to next
    step.

  2. Turn ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. Turn ignition on. Disconnect
    and inspect pedal travel sensor connector. Repair connector as
    necessary. With DRB-II in voltmeter mode, probe Gray/Light Blue wire
    at sensor connector. If no voltage is present, go to next step. If
    voltage is present, repair Gray/Light Blue wire for a short to battery
    voltage. Perform VERIFICATION TEST VER-1A.

  3. Turn ignition off. With DRB-II in ohmmeter mode, probe
    Gray/Light Blue wire at pedal travel sensor connector. If resistance
    is less than
    5 ohms, repair Gray/Light Blue wire for a short to
    ground. Perform VERIFICATION TEST VER-1A. If resistance is more than 5
    ohms, go to next step.

  4. Using an external ohmmeter, measure resistance between CAB
    connector terminal No.
    16 and pedal travel sensor connector Gray/Light
    Blue wire. If resistance is less than 5 ohms, go to next step. If
    resistance is more than
    5 ohms, repair open Gray/Light Blue wire to
    pedal travel sensor. Perform VERIFICATION TEST VER-1A.

  5. Using an external ohmmeter, measure resistance between CAB
    connector terminal No. 41 and pedal travel sensor connector Red/Black
    wire. If resistance is less than
    5 ohms, go to next step. If
    resistance is more than
    5 ohms, repair open Red/Black wire to pedal
    travel sensor. Perform VERIFICATION TEST VER-1A.

  6. Remove pedal travel sensor from brake booster. Check if
    sensor plunger cap color matches color dot on booster (near sensor).
    If colors match, go to next step. If colors do not match, replace
    pedal travel sensor. Perform VERIFICATION TEST VER-1A.

  7. Using an external ohmmeter, measure resistance of pedal
    travel sensor while slowly depressing sensor plunger. If sensor
    resistance is as specified, replace CAB. See PEDAL TRAVEL SENSOR
    RESISTANCE table. Perform VERIFICATION TEST VER-1A. If sensor
    resistance is not as specified, replace pedal travel sensor. Perform
    VERIFICATION TEST VER-1A.

PEDAL TRAVEL SENSOR RESISTANCE TABLE

Plunger Position Ohms

Step 1 (Rest) 236-262

Step 2 414-458

Step 3 534-592

Step 4 655-725

Step 5 776-858

Step 6 980-1084

Step 7 Infinity

TEST15A

PUMP MOTOR CIRCUIT NOT WORKING PROPERLY

1) Inspect ABS pump/motor fuse from Power Distribution Center
(PDC)
. If fuse is okay, go to next step. If fuse is not okay (blown),

perform TEST 15B.

2) Remove ABS pump/motor relay from PDC, and inspect

connector. Repair connector as necessary. With DRB-II in voltmeter mode, probe Red/Dark Green wire (Red/Dark Blue wire on Grand Cherokee and Grand Wagoneer or Red/Brown wire on Wrangler) at ABS pump/motor relay socket terminal "B". If voltage is more than 9 volts, go to next step. If voltage is less than 9 volts, repair open Red/Dark Green wire (Red/Dark Blue wire on Grand Cherokee and Grand Wagoneer or Red/Brown wire on Wrangler) to ABS pump/motor relay.

  1. Connect a jumper wire between Red/Dark Green wire and
    Tan/Black wire (Brown/White wire and Red/Dark Blue wire on Grand
    Cherokee and Grand Wagoneer or Tan wire and Red/Brown wire on
    Wrangler) at ABS pump/motor relay socket terminals "B" and "D". Turn
    ignition on. Inspect ABS pump/motor fuse. If fuse is okay (does not
    blow), go to next step. If fuse is not okay (blows), perform TEST 15B.

  2. Listen for ABS pump/motor operation. If ABS pump/motor is
    running, go to next step. If ABS pump/motor is not running, perform
    TEST 15C.

  3. Turn ignition off. Remove jumper wire. With DRB-II in
    ohmmeter mode, probe Gray/Yellow wire (Gray/Pink wire on Grand
    Cherokee and Grand Wagoneer) at ABS pump/motor relay socket. If
    resistance is less than 5 ohms, go to next step. If resistance is more
    than 5 ohms, repair open Gray/Yellow wire (Gray/Pink wire on Grand
    Cherokee and Grand Wagoneer) wire between ABS pump/motor relay socket
    and ABS main relay. Perform VERIFICATION TEST VER-1A.

  4. Using an external ohmmeter, measure resistance of ABS
    pump/motor relay coil terminals No.
    85 and 86. See Fig. 16. If
    resistance is 35-65 ohms, go to next step. If resistance is not 35-65
    ohms, replace ABS pump/motor relay. Perform VERIFICATION TEST VER-1A.

  5. Disconnect and inspect CAB 55-pin connector. Repair
    connector as necessary. Turn ignition on. With DRB-II in voltmeter
    mode, probe Gray wire at ABS pump/motor relay socket. If no voltage is
    present, go to next step. If any voltage is present, repair Gray wire
    for a short to battery voltage. Perform VERIFICATION TEST VER-1A.

  6. Turn ignition off. With DRB-II in ohmmeter mode, probe
    Gray wire at ABS pump/motor relay socket. If resistance is less than 5
    ohms, repair Gray wire for a short to ground. Perform VERIFICATION
    TEST VER-1A. If resistance is more than 5 ohms, go to next step.

  7. Using an external ohmmeter, measure resistance between CAB
    connector terminal No.
    15 and ABS pump/motor relay socket Gray wire.
    If resistance is less than 5 ohms, go to next step. If resistance is
    more than
    5 ohms, repair open Gray wire to relay socket. Perform
    VERIFICATION TEST VER-1A.


  1. Turn ignition off. Reinstall ABS pump/motor relay in PDC.
    Apply battery voltage to CAB connector terminal No. 15, and go to next
    step.

  2. Ensure ignition is off. With DRB-II in voltmeter mode,
    probe Tan/Black wire (Brown/White wire on Grand Cherokee and Grand
    Wagoneer or Tan wire on Wrangler) at ABS pump/motor 4-pin harness
    connector. If voltage is more than
    9 volts, perform TEST 15D. If
    voltage is less than 9 volts, replace ABS pump/motor relay. Perform
    VERIFICATION TEST VER-1A.

TEST15B

PUMP MOTOR CIRCUIT NOT WORKING PROPERLY

1) Remove ABS pump/motor relay (if installed) from Power
Distribution Center (PDC)
. Remove jumper wire from ABS pump/motor
relay socket (if installed). Turn ignition off, and go to next step.

2) With DRB-II in ohmmeter mode, probe Tan/Black wire
(Brown/White wire on Grand Cherokee and Grand Wagoneer or Tan wire on

Wrangler) at ABS pump/motor relay socket. If resistance is less than 5 ohms, repair Tan/Black wire (Brown/White wire on Grand Cherokee and

Grand Wagoneer or Tan wire on Wrangler) for a short to ground. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, go to next step.

3) Using an external ohmmeter, check ABS pump/motor relay diode. Attach ohmmeter positive and negative leads as shown. See Fig. 17. If continuity exists, replace ABS pump/motor relay. Perform VERIFICATION TEST VER-1A. If no continuity exists, replace ABS pump/motor assembly. Perform VERIFICATION TEST VER-1A.

Fig. 17: Checking ABS Pump/Motor Relay Diode

TEST15C

PUMP MOTOR CIRCUIT NOT WORKING PROPERLY

1) Disconnect ABS pump/motor 4-pin connector at hydraulic
control unit. Ensure jumper wire is still connected between Red/Dark
Green wire and Tan/Black wire (Brown/White wire and Red/Dark Blue wire
on Grand Cherokee and Grand Wagoneer or Tan wire and Red/Brown wire on
Wrangler) at ABS pump/motor relay socket.

2) With DRB-II in voltmeter mode, probe Tan/Black wire
(Brown/White wire on Grand Cherokee and Grand Wagoneer or Tan wire on

Wrangler) at ABS pump/motor 4-pin harness connector. If voltage is more than 9 volts, go to next step. If voltage is less than 9 volts, repair open Tan/Black wire (Brown/White wire on Grand Cherokee and Grand Wagoneer or Tan wire on Wrangler) to 4-pin harness connector. Perform VERIFICATION TEST VER-1A.

3) Turn ignition off. With DRB-II in ohmmeter mode, probe Black/Tan ground wire (Black ground wire on Grand Cherokee and Grand Wagoneer) at ABS pump/motor 4-pin harness connector. If resistance is less than 5 ohms, replace ABS pump/motor assembly. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, repair open in Black/Tan ground wire (Black ground wire on Grand Cherokee and Grand Wagoneer). Perform VERIFICATION TEST VER-1A.

TEST15D

PUMP MOTOR CIRCUIT NOT WORKING PROPERLY

  1. Using an external ohmmeter, measure resistance of ABS
    pump/motor speed sensor. See Fig. 18. If sensor resistance is 10-35
    ohms, go to next step. If resistance is not 10-35 ohms, replace ABS
    pump/motor assembly. Perform VERIFICATION TEST VER-1A.

  2. Turn ignition on. With DRB-II in voltmeter mode, probe Tan
    wire (Light Green/Brown wire on Wrangler) at ABS pump/motor 4-pin
    harness connector. If any voltage is present, repair ABS pump/motor
    speed sensor Tan wire (Light Green wire on Wrangler) for a short to
    battery voltage. Perform VERIFICATION TEST VER-1A. If no voltage is
    present, go to next step.

  3. With DRB-II in voltmeter mode, probe Dark Blue wire (Brown
    wire on Wrangler) at ABS pump/motor 4-pin harness connector. If any
    voltage is present, repair ABS pump/motor speed sensor Dark Blue wire

(Brown wire on Wrangler) for a short to battery voltage. Perform VERIFICATION TEST VER-1A. If no voltage is present, go to next step.

  1. With DRB-II in ohmmeter mode, probe Tan wire (Light
    Green/Brown wire on Wrangler) at ABS pump/motor 4-pin harness
    connector. If resistance is less than
    5 ohms, repair ABS pump/motor
    speed sensor Tan wire (Light Green/Brown wire on Wrangler) for a short
    to ground. Perform VERIFICATION TEST VER-1A. If resistance is more
    than 5 ohms, go to next step.

  2. With DRB-II in ohmmeter mode, probe Dark Blue wire (Brown
    wire on Wrangler) at ABS pump/motor 4-pin harness connector. If
    resistance is less than
    5 ohms, repair ABS pump/motor speed sensor
    Dark Blue wire (Brown wire on Wrangler) for a short to ground. Perform
    VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, go to
    next step.

6) Using an external ohmmeter, measure resistance of Tan wire
(Light Green/Brown wire on Wrangler) between CAB connector terminal

No. 49 and ABS pump/motor 4-pin harness connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open ABS pump/motor speed sensor Tan wire (Light Green/Brown wire on Wrangler). Perform VERIFICATION TEST VER-1A.

7) Using an external ohmmeter, measure resistance of Dark
Blue wire (Brown wire on Wrangler) between CAB connector terminal No.
31 and ABS pump/motor 4-pin harness connector. If resistance is less
than
5 ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If
resistance is more than
5 ohms, repair open ABS pump/motor speed
sensor Dark Blue wire (Brown wire on Wrangler)
. Perform VERIFICATION
TEST VER-1A.

Fig. 18: Checking ABS Pump/Motor Sensor Resistance

TEST16A

RIGHT FRONT INLET VALVE

  1. Disconnect and inspect Hydraulic Control Unit (HCU) 10-pin
    connector. Repair connector as necessary. Turn ignition on. With DRB-
    II in voltmeter mode, probe White/Tan wire (White/Orange wire on Grand
    Cherokee and Grand Wagoneer or White/Yellow wire on Wrangler) at HCU
    10-pin harness connector. If no voltage is present, go to next step.
    If any voltage is present, repair White/Tan wire (White/Orange wire on
    Grand Cherokee and Grand Wagoneer or White/Yellow wire on Wrangler)
    for a short to battery power. Perform VERIFICATION TEST VER-1A.

  2. Turn ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. With DRB-II in ohmmeter
    mode, probe White/Tan wire (White/Orange wire on Grand Cherokee and
    Grand Wagoneer or White/Yellow wire on Wrangler) at HCU 10-pin harness
    connector. If resistance is more than 5 ohms, go to next step. If
    resistance is less than
    5 ohms, repair White/Tan wire (White/Orange
    wire on Grand Cherokee and Grand Wagoneer or White/Yellow wire on
    Wrangler) for a short to ground. Perform VERIFICATION TEST VER-1A.

  3. Using an external ohmmeter, measure resistance of

White/Tan wire (White/Orange wire on Grand Cherokee and Grand Wagoneer or White/Yellow wire on Wrangler) between CAB connector terminal No. 38 and HCU 10-pin harness connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open White/Tan wire (White/Orange wire on Grand Cherokee and Grand Wagoneer or White/Yellow wire on Wrangler). Perform VERIFICATION TEST VER-1A.

4) Using an external ohmmeter, measure resistance of right front inlet valve between terminals No. 3 and 5 at HCU pigtail connector. See Fig. 19. If resistance is 5-8 ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If resistance is not 5-8 ohms, replace hydraulic control unit. Perform VERIFICATION TEST VER-1A.

Fig. 19: Checking HCU Right Front Inlet Valve Resistance

TEST17A

RIGHT FRONT OUTLET VALVE

1) Disconnect and inspect Hydraulic Control Unit (HCU) 10-pin

connector. Repair connector as necessary. Turn ignition on. With DRB-II in voltmeter mode, probe Dark Green/White wire at HCU 10-pin harness connector. If no voltage is present, go to next step. If any voltage is present, repair Dark Green/White wire for a short to battery power. Perform VERIFICATION TEST VER-1A.

  1. Turn ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. With DRB-II in ohmmeter
    mode, probe Dark Green/White wire at HCU 10-pin harness connector. If
    resistance is more than 5 ohms, go to next step. If resistance is less
    than 5 ohms, repair Dark Green/White wire for a short to ground.
    Perform VERIFICATION TEST VER-1A.

  2. Using an external ohmmeter, measure resistance of Dark
    Green/White wire between CAB connector terminal No.
    21 and HCU 10-pin
    harness connector. If resistance is less than 5 ohms, go to next step.
    If resistance is more than 5 ohms, repair open Dark Green/White wire.
    Perform VERIFICATION TEST VER-1A.

  3. Using an external ohmmeter, measure resistance of right
    front outlet valve between terminals No.
    8 and 10 at HCU connector.
    See Fig. 19. If resistance is 3-5 ohms, replace CAB. Perform
    VERIFICATION TEST VER-1A. If resistance is not
    3-5 ohms, replace
    hydraulic control unit. Perform VERIFICATION TEST VER-1A.

TEST18A

RIGHT FRONT SENSOR CIRCUIT FAILURE

1) Using DRB-II, read and record all wheel speed sensor

faults. If RIGHT FRONT SENSOR CIRCUIT FAILURE message is displayed, go to next step. If message is not displayed, perform TEST 19A.

  1. Inspect right front wheel speed sensor for damage. If
    sensor is okay, go to next step. If sensor is damaged, repair or
    replace as necessary. Perform VERIFICATION TEST VER-1A.

  2. Turn ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. Turn ignition on. With DRB-
    II in voltmeter mode, probe White wire at CAB connector terminal No.
    47. If no voltage is present, go to next step. If any voltage is
    present, repair White wire for a short to battery power. Perform
    VERIFICATION TEST VER-1A.

  3. Turn ignition off. With DRB-II in ohmmeter mode, probe
    White wire at CAB connector terminal No.
    47. If resistance is more
    than 5 ohms, go to next step. If resistance is less than 5 ohms,
    repair White wire for a short to ground. Perform VERIFICATION TEST
    VER-1A.

  4. Using an external ohmmeter, measure resistance of right
    front wheel speed sensor between White/Dark Blue wire and White wire
    at CAB connector terminals No.
    29 and 47. If resistance is 900-1300
    ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If resistance is
    not
    900-1300 ohms, go to next step.

  5. Disconnect right front wheel speed sensor harness
    connector. Connector is located on right rear corner of engine
    compartment. Using an external ohmmeter, measure resistance of right
    front wheel speed sensor at harness connector terminals. If resistance
    is
    900-1300 ohms, go to next step. If resistance is not 900-1300 ohms,
    replace sensor. Perform VERIFICATION TEST VER-1A.

  6. Using an external ohmmeter, measure resistance of White
    wire between CAB connector terminal No.
    47 and right front wheel speed
    sensor harness connector. If resistance is less than
    5 ohms, repair
    open White/Dark Blue wire. Perform VERIFICATION TEST VER-1A. If
    resistance is more than
    5 ohms, repair open White wire. Perform
    VERIFICATION TEST VER-1A.

TEST19A

RIGHT FRONT SENSOR

  1. Inspect right front wheel speed sensor for damage. If
    sensor is okay, go to next step. If sensor is damaged, repair or
    replace as necessary. Perform VERIFICATION TEST VER-1A.

  2. Inspect right front wheel speed sensor tone (pulse) ring
    for damaged teeth or excessive runout. Runout should not exceed .003"
    (.08 mm). Repair or replace tone ring as necessary. Perform

VERIFICATION TEST VER-1A. If tone ring is okay, go to next step.

  1. Using a feeler gauge, check right front wheel sensor-to-
    tone ring clearance. If clearance is
    .036-.050" (.91-1.27 mm), go to
    next step. If clearance is not .036-.050" (.91-1.27 mm), repair as
    necessary. Perform VERIFICATION TEST VER-1A.

  2. Inspect right front wheel speed sensor wiring harness for
    damage. If wiring harness is okay, go to next step. If wiring harness
    is damaged, repair wiring harness as necessary. Perform VERIFICATION
    TEST VER-1A.

  3. Disconnect right front wheel speed sensor harness
    connector. Connector is located on right rear corner of engine
    compartment. Using an external ohmmeter, measure resistance of right
    front wheel speed sensor at harness connector terminals. If resistance
    is 900-1300 ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If
    resistance is not
    900-1300 ohms, replace sensor. Perform VERIFICATION
    TEST VER-1A.

NOTE: If excessive axle deflection occurs on extremely bumpy

surfaces or during off road use, it is possible for a wheel speed sensor to set a code.

TEST 20A

RIGHT REAR SENSOR CIRCUIT FAILURE

  1. Using DRB-II, read and record all wheel speed sensor
    faults. If RIGHT REAR SENSOR CIRCUIT FAILURE message is displayed, go
    to next step. If message is not displayed, perform TEST 21A.

  2. Inspect right rear wheel speed sensor for damage. If
    sensor is okay, go to next step. If sensor is damaged, repair or
    replace as necessary. Perform VERIFICATION TEST VER-1A.

  3. Turn ignition off. Disconnect and inspect CAB 55-pin

connector. Repair connector as necessary. Turn ignition on. Using DRB-II in voltmeter mode, probe Yellow wire (Yellow/Dark Blue wire on Wrangler) at CAB connector terminal No. 27. If no voltage is present, go to next step. If any voltage is present, perform TEST 20B.

4) Using DRB-II in ohmmeter mode, probe Yellow wire

(Yellow/Dark Blue wire on Wrangler) at CAB connector terminal No. 27. If resistance is more than 5 ohms, go to next step. If resistance is less than 5 ohms, perform TEST 20C.

  1. Using an external ohmmeter, measure resistance of right
    rear wheel speed sensor between Yellow wire and Yellow/Dark Blue wire
    at CAB connector terminals No. 27 and 45. If resistance is 900-1300
    ohms, replace CAB. Perform VERIFICATION TEST VER-1A. If resistance is
    not
    900-1300 ohms, go to next step.

  2. Disconnect right rear wheel speed sensor. Using an
    external ohmmeter, measure resistance of right rear wheel speed
    sensor. If resistance is 900-1300 ohms, go to next step. If resistance
    is not 900-1300 ohms, replace sensor. Perform VERIFICATION TEST VER-
    1A.

  3. Connect a jumper wire between ground and Yellow/Dark Blue

wire (Yellow wire on Wrangler) at CAB connector terminal No. 45. With DRB-II in ohmmeter mode, measure resistance of Yellow wire (Yellow/Dark Blue wire on Wrangler) at right rear wheel speed sensor harness connector. If resistance is less than 5 ohms, perform TEST 20E. If resistance is more than 5 ohms, perform TEST 20D.

TEST 20B

RIGHT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee, repair Yellow wire for a short to battery
    power. Perform VERIFICATION TEST VER-1A. On Wrangler, repair
    Yellow/Dark Blue wire for a short to battery power. Perform
    VERIFICATION TEST VER-1A. On Grand Cherokee and Grand Wagoneer,
    disconnect and inspect Black ABS 8-pin disconnect connector. Connector
    is located behind left kick panel. Repair connector as necessary. With
    DRB-II in voltmeter mode, probe Yellow wire of ABS disconnect
    connector.

  2. If no voltage is present, repair Yellow wire for a short
    to battery power between right rear wheel speed sensor and ABS
    disconnect connector. Perform VERIFICATION TEST VER-1A. If any voltage
    is present, repair Yellow wire for a short to battery power between
    ABS disconnect connector and CAB 55-pin connector. Perform
    VERIFICATION TEST VER-1A.

TEST 20C

RIGHT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee, repair Yellow wire for a short to ground.
    Perform VERIFICATION TEST VER-1A. On Wrangler, repair Yellow/Dark Blue
    wire for a short to ground. Perform VERIFICATION TEST VER-1A. On Grand
    Cherokee and Grand Wagoneer, disconnect and inspect Black ABS 8-pin
    disconnect connector. Connector is located behind left side kick
    panel. Repair connector as necessary. With DRB-II in ohmmeter mode,
    probe Yellow wire of ABS disconnect connector.

  2. If resistance is less than 5 ohms, repair Yellow wire for
    a short to ground between right rear wheel speed sensor and ABS
    disconnect connector. Perform VERIFICATION TEST VER-1A. If resistance
    is more than
    5 ohms, repair Yellow wire for a short to ground between
    ABS disconnect connector and CAB 55-pin connector. Perform
    VERIFICATION TEST VER-1A.

TEST 20D

RIGHT REAR SENSOR CIRCUIT FAILURE

  1. On Cherokee, repair open Yellow/Dark Blue wire to right
    rear wheel speed sensor. Perform VERIFICATION TEST VER-1A. On
    Wrangler, repair open Yellow wire to right rear wheel speed sensor.
    Perform VERIFICATION TEST VER-1A. On Grand Cherokee and Grand
    Wagoneer, disconnect and inspect Black ABS 8-pin disconnect connector.
    Connector is located behind left kick panel. Repair connector as
    necessary. With DRB-II in ohmmeter mode, probe Yellow/Dark Blue wire
    of ABS disconnect connector.

  2. If resistance is less than 5 ohms, repair open Yellow/Dark
    Blue wire between right rear wheel speed sensor and ABS disconnect
    connector. Perform VERIFICATION TEST VER-1A. If resistance is more
    than
    5 ohms, repair open Yellow/Dark Blue wire between ABS disconnect
    connector and CAB 55-pin connector. Perform VERIFICATION TEST VER-1A.

TEST 20E

RIGHT REAR SENSOR CIRCUIT FAILURE

  1. On Wrangler, repair open Yellow/Dark Blue wire to right
    rear wheel speed sensor. Perform VERIFICATION TEST VER-1A. On all
    others, disconnect and inspect Black ABS 8-pin disconnect connector.
    On Cherokee, connector is located on transmission hump near firewall.
    On Grand Cherokee and Grand Wagoneer, connector is located behind left
    side kick panel. Repair connector as necessary. Connect a jumper wire
    between ground and Yellow wire at CAB connector terminal No.
    27. With
    DRB-II in ohmmeter mode, probe Yellow wire of ABS disconnect
    connector.

  2. If resistance is less than 5 ohms, repair open Yellow wire
    between right rear wheel speed sensor and ABS disconnect connector.
    Perform VERIFICATION TEST VER-1A. If resistance is more than
    5 ohms,
    repair open Yellow wire between ABS disconnect connector and CAB 55-
    pin connector. Perform VERIFICATION TEST VER-1A.

TEST 21A

RIGHT REAR SENSOR

  1. Inspect right rear wheel speed sensor for damage. If
    sensor is okay, go to next step. If sensor is damaged, repair or
    replace as necessary. Perform VERIFICATION TEST VER-1A.

  2. Inspect right rear wheel speed sensor tone (pulse) ring
    for damaged teeth and excessive runout. Runout should not exceed .003"
    (.08 mm). Repair or replace tone ring as necessary. Perform

VERIFICATION TEST VER-1A. If tone ring is okay, go to next step.

  1. Using a feeler gauge, check right rear wheel sensor-to-
    tone ring clearance. If clearance is .036-.050" (.91-1.27 mm), go to
    next step. If clearance is not .036-.050" (.91-1.27 mm), repair as
    necessary. Perform VERIFICATION TEST VER-1A.

  2. Inspect right rear wheel speed sensor wiring harness for
    damage. If wiring harness is okay, go to next step. If wiring harness
    is damaged, repair wiring harness as necessary. Perform VERIFICATION
    TEST VER-1A.

  3. Disconnect right rear wheel speed sensor. Using an
    external ohmmeter, measure resistance of right rear wheel speed
    sensor. If resistance is
    900-1300 ohms, replace CAB. Perform
    VERIFICATION TEST VER-1A. If resistance is not 900-1300 ohms, replace
    sensor. Perform VERIFICATION TEST VER-1A.

NOTE: If excessive axle deflection occurs on extremely bumpy

surfaces or during off road use, it is possible for a wheel speed sensor to set a code.

TEST 22A

ABS WARNING LIGHT ILLUMINATION PROBLEM

1) Using DRB-II, read ABS fault codes. If any fault codes are present, perform TEST 1A. Turn ignition off. Remove ABS main relay from PDC, and inspect connector. Repair connector as necessary. Turn ignition on. If ABS warning light comes on, go to next step. If warning light does not come on, perform VERIFICATION TEST VER-1C.

NOTE: A main relay/power circuit failure fault will set with ABS

main relay removed.

  1. Turn ignition off. With DRB-II in ohmmeter mode, probe
    Black/Tan ground wire (Black ground wire on Grand Cherokee and Grand
    Wagoneer) at ABS main relay socket. If resistance is less than 5 ohms,
    go to next step. If resistance is more than 5 ohms, repair open
    Black/Tan ground wire (Black ground wire on Grand Cherokee and Grand
    Wagoneer)
    . Perform VERIFICATION TEST VER-1A.

  2. Ensure ignition off. Disconnect and inspect CAB 55-pin
    connector. Repair connector as necessary. With DRB-II in voltmeter
    mode, probe Gray/Yellow wire (Gray/Pink wire on Grand Cherokee and
    Grand Wagoneer) at ABS main relay socket. If no voltage is present, go
    to next step. If any voltage is present, replace ABS main relay.
    Perform VERIFICATION TEST VER-1A.

  3. Remove ABS diode. Diode is taped to wiring harness, near
    CAB (near ABS 8-pin disconnect connector on Grand Cherokee and Grand
    Wagoneer)
    . Connect a jumper wire between Gray/Yellow wire (Gray/Pink
    wire on Grand Cherokee and Grand Wagoneer) and Black/Tan wire (Black
    wire on Grand Cherokee and Grand Wagoneer) at ABS main relay socket
    terminals "B" and "E".

  4. Using DRB-II in ohmmeter mode, probe Gray/Yellow wire at
    ABS diode connector. If resistance is less than
    5 ohms, go to next
    step. If resistance is more than 5 ohms, repair open Gray/Yellow wire
    between relay splice and diode. Perform VERIFICATION TEST VER-1A.

  5. Remove jumper wire used in step 4). Turn ignition on. If
    ABS warning light does not come on, go to next step. If ABS warning
    light comes on, repair Violet wire (Violet/White wire on Grand
    Cherokee and Grand Wagoneer or Light Green/Orange on Wrangler) for a
    short circuit to ground between CAB connector terminal No. 52 and ABS
    diode.

  6. Turn ignition off. Connect a jumper wire between ground
    and Violet wire (Violet/White wire on Grand Cherokee and Grand
    Wagoneer or Light Green/Orange wire on Wrangler) at CAB connector
    terminal No.
    52. Using DRB-II in ohmmeter mode, probe Violet wire

(Violet/White wire on Grand Cherokee and Grand Wagoneer or Light Green/Orange wire on Wrangler) at ABS diode connector. If resistance is less than 5 ohms, replace ABS diode. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, repair open Violet wire

(Violet/White wire on Grand Cherokee and Grand Wagoneer or Light Green/Orange wire on Wrangler) between ABS warning light and diode. Perform VERIFICATION TEST VER-1A.

TEST 23A

NO RESPONSE MESSAGE

  1. On Cherokee, remove and inspect fuse No. 7. If fuse is
    blown, check for possible short to ground in Light Green/Yellow wire
    between ignition switch and terminal No.
    53 of CAB connector. If fuse
    is okay, go to next step. On Grand Cherokee and Grand Wagoneer, remove
    and inspect fuse No.
    15. If fuse is blown, check for possible short to
    ground in Light Green/Yellow wire between ignition switch and terminal
    No. 53 of CAB connector. If fuse is okay, go to next step. On
    Wrangler, remove and inspect fuse No.
    13. If fuse is blown, check for
    possible short to ground in Yellow/Dark Green wire between ignition
    switch and terminal No.
    53 of CAB connector. If fuse is okay, go to
    next step.

  2. On all models, turn ignition off. Disconnect and inspect
    CAB 55-pin connector. Repair connector as necessary. Turn ignition on.
    With DRB-II in voltmeter mode, probe terminal No. 53 (Light
    Green/Yellow wire on Cherokee and Grand Cherokee and Grand Wagoneer or
    Yellow/Dark Green wire on Wrangler) of CAB connector.

  3. If voltage is less than 9 volts, repair open in Light
    Green/Yellow wire (Cherokee and Grand Cherokee and Grand Wagoneer) or
    Yellow/Dark Green wire (Wrangler)
    . Perform VERIFICATION TEST VER-1A.
    If voltage is more than 9 volts, turn ignition off. With DRB-II in
    ohmmeter mode, probe terminal No. 1 (Black wire) of CAB connector. If
    resistance is more than 5 ohms, repair open Black wire. Perform
    VERIFICATION TEST VER-1A.

  4. If resistance is less than 5 ohms, probe terminal No. 19
    (Black wire) of CAB connector. If resistance is more than 5 ohms,
    repair open Black wire. Perform VERIFICATION TEST VER-1A. If
    resistance is less than 5 ohms, check resistance of Violet/Brown wire
    (White/Violet wire on Wrangler) between terminals No.
    4 of CCD bus

diagnostic connector and No. 23 of CAB connector using an external ohmmeter.

  1. If resistance is more than 5 ohms, repair open in
    Violet/Brown wire (White/Violet wire on Wrangler). Perform
    VERIFICATION TEST VER-1A. If resistance is less than
    5 ohms, using an
    external ohmmeter, check resistance of White/Black wire on Cherokee,
    White/Gray wire on Grand Cherokee and Grand Wagoneer or Orange wire on
    Wrangler between terminal No. 3 of CCD bus diagnostic connector and
    No. 42 of CAB connector.

  2. If resistance is more than 54 ohms, repair open in

White/Black wire (Cherokee), White/Gray wire (Grand Cherokee and Grand Wagoneer) or Orange wire (Wrangler). Perform VERIFICATION TEST VER-1A. If resistance is less than 5 ohms, turn ignition off. Reconnect CAB 55-pin connector. Using DRB-II, try to access ABS TEVES diagnostics. If DRB-II does not display NO RESPONSE, system is functioning properly. If DRB-II displays NO RESPONSE, replace CAB. Perform VERIFICATION TEST VER-1A.

VERIFICATION TEST VER-1A

SYSTEM VERIFICATION TEST

  1. Disconnect all previously connected jumper wires.
    Reconnect all previously disconnected connectors. Reinstall all
    previously removed relays. Replace any blown fuses. Using DRB-II,
    erase fault messages. Cycle ignition off and then on. Using DRB-II,
    monitor read faults display for 3 minutes. If DRB-II displays any
    faults, perform TEST 1A.

  2. If DRB-II does not display any faults, using DRB-II, read
    brakelight switch input. Depress brake pedal. If DRB-II does not
    display PRESSED, perform VERIFICATION TEST VER-1B. If DRB-II displays
    PRESSED, using DRB-II, read "G" SWITCH input. If DRB-II does not
    display "G" SWITCH #1 CLOSED, "G" SWITCH #2 CLOSED, perform TEST 3A.

  3. If DRB-II displays No. 1 and 2 "G" switch CLOSED, with
    DRB-II in ABS TEVES diagnostic mode, check ANTI-LOCK warning light. If
    warning light is off, perform, VERIFICATION TEST VER-1C. If warning
    light is flashing, depress brake pedal. Using DRB-II, actuate left
    front outlet valve.

  4. If brake pedal "drop" was not felt when valve was

actuated, replace hydraulic control unit. Perform VERIFICATION TEST VER-1A. If brake pedal "drop" was felt when valve was actuated, release brake pedal. Depress brake pedal. Using DRB-II, actuate right front outlet valve.

5) If brake pedal "drop" was not felt when valve was

actuated, replace hydraulic control unit. Perform VERIFICATION TEST VER-1A. If brake pedal "drop" was felt when valve was actuated, release brake pedal. Depress brake pedal. Using DRB-II, actuate rear outlet valve.

6) If brake pedal "drop" was not felt when valve was
actuated, replace hydraulic control unit. Perform VERIFICATION TEST

VER-1A. If brake pedal "drop" was felt when valve was actuated, road test vehicle for a minimum of 5 minutes and perform several anti-lock braking stops.

7) Using DRB-II, read fault messages. If DRB-II displays any faults, perform TEST 1A. If DRB-II displays no faults, system is operating properly.

VERIFICATION TEST VER-1B

BRAKELIGHT SWITCH SENSOR CIRCUIT

  1. Check brakelight operation. If brakelights are not
    operating properly, repair as necessary. Perform VERIFICATION TEST
    VER-1A. If brakelights are operating properly, turn ignition off.
    Disconnect and inspect CAB 55-pin connector. Repair connector as
    necessary.

  2. Depress brake pedal. With DRB-II in voltmeter mode, probe
    terminal No.
    32 (White/Tan wire) of CAB connector. If voltage is less
    than 9 volts, repair open White/Tan wire. Perform VERIFICATION TEST
    VER-1A. If voltage is more than 9 volts, replace CAB. Perform
    VERIFICATION TEST VER-1A.

VERIFICATION TEST VER-1 C

ANTI-LOCK WARNING LIGHT CIRCUIT

  1. Set parking brake. Turn ignition on. If Red BRAKE warning
    light is off, repair fused ignition feed circuit to warning lights.
    Perform VERIFICATION TEST VER-1A. If Red BRAKE warning light is on,
    turn ignition off. Disconnect and inspect CAB 55-pin connector. Repair
    connector as necessary.

  2. Turn ignition on. Connect a jumper wire between terminal
    No. 52 (Violet wire on Cherokee or Violet/White wire on Grand Cherokee
    and Grand Wagoneer or Light Green/Orange wire on Wrangler) and ground.
    Check ANTI-LOCK warning light. If ANTI-LOCK warning light is on,
    replace CAB. Perform VERIFICATION TEST VER-1A.

  3. If ANTI-LOCK warning light is off, inspect ANTI-LOCK
    warning light bulb. Replace bulb as necessary. Perform VERIFICATION
    TEST VER-1A. If bulb is okay, repair open Violet wire (Cherokee) or
    Violet/White wire (Grand Cherokee and Grand Wagoneer) or Light
    Green/Orange wire (Wrangler)
    . Perform VERIFICATION TEST VER-1A.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS TABLE

Application Ft. Lbs. (N.m)

Combination Valve Brakeline Fittings 13-18 (18-24)

Front Speed Sensor Bolt 11 (15)

HCU Brakeline Fittings 10-12 (14-16)

Master Cylinder Brakeline Fittings 11-13 (15-18)

Rear Speed Sensor Bolt 11 (15)

Wheel Lug Nuts 88 (119)

INCH Lbs. (N.m)

CAB Mounting Bolts 75-115 (9-13)

"G" Switch Bolt 17-32 (2-4)

HCU Bracket Mounting Bolts 92-112 (10-13)

WIRING DIAGRAMS

Fig. 20: ABS Wiring Diagram (Cherokee)

93.T75803

Fig. 21: ABS Wiring Diagram (Grand Cherokee

& Grand Wagoneer)

93A75804 Fig. 22: ABS Wiring Diagram (Wrangler)