Electronic Overhead Module (EOM)

U0019-CAN B BUS







- When Monitored:
Continuously.

- Set Condition:
Whenever the Can B Bus (+) or Can B Bus (-) circuit is open, shorted to voltage or shorted to ground, this code will set.





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

Does the scan tool display U0019-CAN B BUS?

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.
- Perform the BODY VERIFICATION TEST. Body Verification Test

2. CHECK FRONT CONTROL MODULE DTCs
1. With the scan tool, read Front Control Module 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. (D55) CAN B BUS (+) CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the Electronic Overhead Module (CMTC) harness connector.
3. Disconnect the Front Control Module C1 harness connector.
4. Measure the resistance of the (D55) Can B Bus (+) circuit between the Front Control Module C1 harness connector and the Electronic Overhead Module (CMTC) 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. (D54) CAN B BUS (-) CIRCUIT OPEN




1. Measure the resistance of the (D54) Can B Bus (-) circuit between the Front Control Module C1 harness connector and the Electronic Overhead Module (CMTC) harness connector.

Is the resistance below 2.0 ohms?

Yes

- Replace the Electronic Overhead 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