ABS - Fault Code Clearing/Manual Revision

89AMC/jeep02

Models


1989 Jeep XJ Equipped With Anti-Lock Brakes


Subject


Clearing "False" Fault Codes Registered During Vehicle Shipment And Service Manual Revision


Index


BRAKES


Date

December 30, 1988

No.


05-52-88

P-5487 (C05-53)

FIGURE 1 - FUSE PANEL:

BODY CODE LEGEND

XJ - Cherokee, Wagoneer

SYMPTOM/CONDITION

During shipment to the dealers, the 1989 Jeep XJ vehicles equipped with the Anti-Lock Brake System (ABS) might register "false" fault codes in the Electronic Control Unit (ECU) memory. The ECU memory should be cleared at the Pre-Delivery Inspection (PDI) to prevent any mis-diagnosis should a customer encounter any future problems.

The ECU memory can be cleared by removing the 2 amp ABS BAT fuse from the fuse panel (fuse no. 10) for 5 seconds (Fig. 1). Once the initial faults are cleared, any "true" faults will reset during the PDI road test.

The following pages contain information to update the Jeep ABS Service Manual Supplement.
Page 14 of the 1989 Service Manual Supplement (#81-370-9045A) has been revised to reflect the information on page one of this bulletin. Page 15 of the same manual has been revised to correct the indicator light color reference. Please permanently affix the attached pages in the Jeep Anti-Lock Brake System Service Manual Supplement. The corrections are printed in red.

NOTE: THE JEEP ABS PUMP/MOTORS EXHIBIT VARYING DEGREES OF MOTOR NOISE DURING OPERATION, THIS IS CONSIDERED NORMAL AND IS NOT AN INDICATION OF A DEFECTIVE PUMP/MOTOR.

Before attempting repairs on the Jeep ABS system be sure to review the Service Diagnosis section of the Anti-Lock Brake System Service Manual Supplement. Familiarize yourself with the operational situations where a driver may induce a fault into an anti-lock system that is operating correctly.


POLICY: Information only.



14 ANTI-LOCK BRAKE SYSTEM-------------------------------J
the fault. The lights signal low fluid levels, pressure drops and other hydro-electrical faults. Refer to the Service Diagnosis charts for indicator light display modes when a fault is detected. The visual examination requires a check of reservoir fluid level and all system components to confirm or rule out leaks, loose connections, or mechanical component failures as a problem cause. The final diagnosis step requires the use of the DRB II tester to determine the specific circuit at fault. The tester is connected to the diagnostic connectors on the passenger side of the engine compartment (Fig. 14). Refer to the DRB II Tester Manual section on anti-lock
system diagnosis for procedures. Faults read by the DRB II tester at initial tester reading should be used as a diagnosis guide only. Initial faults should be cleared and the vehicle road tested to reset any faults that remain in the system. Faults can be cleared by removing the 2 amp "ABS BAT" fuse from the fuse panel (fuse no. 10) for five seconds.