U1000

U1000-CAN B BUS (+) CIRCUIT OPEN





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With the ignition on and battery voltage between 10 and 16 volts.

- Set Condition:
Whenever the (D55) CAN B Bus (+) or (D54) CAN B Bus (-) circuit is open.





1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase Door Module DTCs.
3. Cycle the ignition from on to off three times.
4. Turn the ignition on.
5. With the scan tool, read the active Door Module DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors in the CAN B BUS (+) circuit. Look for broken, bent, pushed out or corroded terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. ATTEMPT TO ISOLATE THE OPEN (D55) CAN B BUS (+) CIRCUIT




1. Turn the ignition on.
2. Verify that all CAN B Bus modules are communicating with the scan tool.

NOTE: A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

NOTE: If any module is not communicating, perform the appropriate no response test procedure before proceeding.

3. Turn the ignition off.
4. Gain access to the Door Module C2 harness connector, but DO NOT DISCONNECT.
5. Using a fused jumper wire, connect one end to ground and with the other end BACKPROBE the (D54) CAN B Bus (-) circuit at the Door Module C2 harness connector.

NOTE: The graphic shows the terminal end of the connector, backprobe the wire end.

6. Turn the ignition on.
7. With the scan tool, monitor the network status screen and document all modules that display a red X.

Are there multiple red X's displayed next to the modules?

Yes

- The most likely cause of this condition is an open (D55) CAN B Bus (+) circuit between a common CAN B Bus splice and the modules that display the red X next to them. Use the wiring diagrams to help you determine where the open condition exists.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. (D55) CAN B BUS (+) CIRCUIT OPEN - SINGLE RED X
1. Turn the ignition off.
2. Disconnect the module that has the red X displayed next to it.
3. Turn the ignition on.
4. Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.

Is there any voltage present?

Yes

- Inspect the connector and terminal for damage, inspect for spread terminals, or pushed out terminals. If ok, replace the module that displayed the red X next to it.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the (D55) CAN B Bus (+) circuit for an open between the next common splice and the module that has the red X displayed next to it. Use the wiring diagrams to help you determine where the open condition exists.
- Perform the BODY VERIFICATION TEST. Body Verification Test.