U0168
U0168-LOST COMMUNICATION WITH VEHICLE SECURITY CONTROL MODULE (WCM)
- When Monitored:
With the ignition on.
Battery voltage between 10 and 16 volts.
Ignition Off Draw (IOD) fused installed.
Totally Integrated Power Module (TIPM) is configured correctly.
- Set Condition:
Bus messages not received from the Wireless Control Module (WCM) for approximately two to five seconds.
1. VERIFY THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
NOTE: Make sure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.
1. With the scan tool, read active DTCs.
Is this DTC active?
Yes
- Go To 2
No
- Stored Lost Communication DTCs Perform the STORED LOST COMMUNICATION DTCS diagnostic procedure.
2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS
1. With the scan tool, read all active DTCs from all modules.
NOTE: Check for TIPM configuration, 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
- Go to and perform the appropriate diagnostic procedure.
No
- Go To 3
3. VERIFY THE WCM IS ACTIVE ON THE BUS
1. Turn the ignition on.
2. With the scan tool, select Network Diagnostics.
3. Verify the WCM is active on the bus.
Is the WCM active on the bus?
Yes
- Go To 4
No
- No Response From WCM (Sentry Key Remote Entry Module) Perform the NO RESPONSE FROM WCM diagnostic procedure.
4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS
1. With the scan tool, select Network Diagnostics.
Is there more than one module with active DTCs "Logged Against" the WCM?
Yes
- Replace/update the WCM.
- Perform the WIRELESS CONTROL MODULE (WCM) VERIFICATION TEST. Wireless Control Module (WCM) Verification Test.
No
- Go To 5
5. CLEAR DTC IN MODULE SETTING FAULT
1. With the scan tool, select the module setting the DTC against the WCM.
2. Clear active DTCs.
Is this DTC still active?
Yes
- Replace/update the module that set this DTC.
- Perform the appropriate verification test for the module being replaced. Verification Tests If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 6
6. CYCLE IGNITION
1. Cycle the ignition from RUN to OFF three time ending with the key in the RUN position.
Does this DTC become active?
Yes
- Go To 7
No
- The condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
7. CHECK FOR ADDITIONAL LOST COMMUNICATION FAULTS
1. With the scan tool, select Network Diagnostics.
Does the TIPM and other CAN C BUS modules show Lost Communication with the remaining CAN C BUS modules?
Yes
- Go To 8
No
- Replace/update the module that set this DTC.
- Perform the appropriate verification test for the module being replaced. Verification Tests If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Body Verification Test.
8. (D65) CAN C BUS (+) CIRCUIT SHORTED TO VOLTAGE
1. Measure the voltage between the (D65) CAN C Bus (+) circuit and ground.
Is the voltage above 5.0 volts?
Yes
- Repair the (D65) CAN C Bus (+) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 9
9. (D64) CAN C BUS (-) CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the (D64) CAN C Bus (-) circuit.
Is the resistance below 10k Ohms?
Yes
- Repair the (D64) CAN C Bus (-) circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Replace/update the module that set this DTC.
- Perform the appropriate verification test for the module being replaced. Verification Tests If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Body Verification Test.