Jeep Liberty KJ. Manual - part 638
•
When Monitored:
Ignition on.
•
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.
ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1417-IMPLAUSIBLE LEFT WHEEL DISTANCE SIGNAL RECEIVED active at this time?
Yes
>> Go To 2
No
>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.
ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Yes
>> Go To 3
No
>> (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING)
3.
DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Yes
>> Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1 (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING)
No
>> Go to 4
9 - 610
ENGINE ELECTRICAL DIAGNOSTICS
KJ