Jeep Grand Cherokee WK. Manual — part 1125

U0114-LOST COMMUNICATION WITH FINAL DRIVE CONTROL MODULE

9 - 1096

ENGINE ELECTRICAL DIAGNOSTICS

WK

U0114-LOST COMMUNICATION WITH FINAL DRIVE CONTROL MODULE (CONTINUED)

For a complete wiring diagramRefer to Section 8W.

•

When Monitored:
Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater
than 3 seconds.

•

Set Condition:
The PCM doesn’t receive a FDCM message over the CAN C circuit for 7 consecutive seconds. The circuit is
continuously monitored.

Possible Causes

CAN C BUS OPEN OR SHORTED CONDITION

FINAL DRIVE CONTROL MODULE

FCM

PCM

Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic
procedures and for further possible causes.

Diagnostic Test

1.

ACTIVE DTC

Ignition on, engine not running.

With a scan tool, read PCM DTCs.

Is the DTC active at this time?

Yes

>> Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diag-

nostic procedures and for further possible causes.

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

WK

ENGINE ELECTRICAL DIAGNOSTICS

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U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE

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ENGINE ELECTRICAL DIAGNOSTICS

WK

U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE (CONTINUED)

For a complete wiring diagramRefer to Section 8W.

•

When Monitored:
Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater
than 3 seconds.

•

Set Condition:
The PCM doesn’t receive an ABS message over the CAN C circuit for 7 consecutive seconds. The circuit is
continuously monitored.

Possible Causes

CAN C BUS OPEN OR SHORTED CONDITION

ABS MODULE

FCM

PCM

Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic
procedures and for further possible causes.

Diagnostic Test

1.

ACTIVE DTC

Ignition on, engine not running.

With a scan tool, read PCM DTCs.

Is the DTC active at this time?

Yes

>> Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diag-

nostic procedures and for further possible causes.

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

WK

ENGINE ELECTRICAL DIAGNOSTICS

9 - 1099