Wireless Control Module (WCM)
U0019-CAN B BUS
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
- When Monitored:
Continuously
- Set Condition:
If the CAN B Bus (+) or CAN B Bus (-) circuit is open, shorted to voltage, or shorted to ground.
1. VERIFY THAT THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
1. Turn the ignition on.
2. With the scan tool, read the active DTCs.
3. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
4. With the scan tool, read the active DTCs.
Does the scan tool display this DTC as active?
Yes
- Go To 2
No
- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. CHECK FOR TOTALLY INTEGRATED POWER MODULE (TIPM) DTCs
1. With the scan tool, read TIPM active DTCs
Does the scan tool display any CAN B BUS DTCs - ACTIVE?
Yes
- Go to and perform the appropriate diagnostic procedure. Testing and Inspection
No
- Go To 3
3. CHECK THE (D55) CAN B BUS (+) CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the negative battery cable.
3. Disconnect the WCM/SKREEM harness connector.
4. Disconnect the TIPM C6 harness connector.
5. Measure the resistance of the (D55) CAN B Bus (+) circuit between the TIPM C6 harness connector and the WCM/SKREEM harness connector.
Is the resistance below 2.0 ohms?
Yes
- Go To 4
No
- Repair the (D55) CAN B Bus (+) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test
4. CHECK THE (D54) CAN B BUS (-) CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D54) CAN B Bus (-) circuit between the TIPM C6 harness connector and the WCM/SKREEM harness connector.
Is the resistance below 2.0 ohms?
Yes
- Replace the Wireless Control Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test
No
- Repair the (D54) CAN B Bus (-) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test