2007 Liberty KJ Factory Service Manual 9 - ENGINE

U0168-LOST COMMUNICATION WITH SKIM/SKREEM (WCM)

For a complete wiring diagram Refer to Section 8W.

When Monitored:

With the ignition on
Battery voltage between 10 and 16 volts
IOD fuse installed

Set Condition:
If the PCM fails to receive bus messages from the SKREEM (WCM) for approximately 500 ms.

Possible Causes

DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES

CAN C BUS CIRCUITS OPEN OR SHORTED

SKREEM (WCM) POWER AND GROUND

Diagnostic Test

1. VERIFY DTC IS ACTIVE

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

Turn the ignition on.
With the scan tool, read active DTCs.

Is this DTC active?

Yes

Go To 2

No

Perform the Stored Lost Communication test procedure. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING).

2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS

With the scan tool, read all active DTCs from all CAN C Bus modules.

NOTE: Check for CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs to the conditions listed above?

Yes

Diagnose and repair the DTC(s). Refer to the Table of Contents in the applicable Section.

No

Go To 3

3. VERIFY THAT THE SKREEM (WCM) IS ACTIVE ON THE BUS

With the scan tool, select ECU View.
Verify that the SKREEM (WCM) is active on the bus.

Is the SKREEM (WCM) active on the bus?

Yes

Go To 4

No

(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No Response related diagnostic procedures.

4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS

With the scan tool, select Network View and select Advanced.

Is there more than one module with active DTCs “Logged Against” the SKREEM (WCM)?

Yes

Replace/update the SKREEM (WCM) in accordance with the service information.

Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).

No

Replace the PCM in accordance with the service information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).