Diagnostic Test
- 1) TEST FOR INTERMITTENT CONDITION
Turn the ignition on.
With the scan tool, record and erase DTCs
Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read DTCs.
Does the scan tool display U0019-CAN B BUS CIRCUIT?
Yes
- Go To step 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 BODY VERIFICATION TEST - VER 1 .
- 2) CHECK FRONT CONTROL MODULE DTCs
With the scan tool, read Front Control Module DTCs
Does the scan tool display any CAN B BUS DTCs - ACTIVE?
Yes
- Refer to the symptom list for problems related to Communication in ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS .
No
- Go to step 3).
- 3) CAN B BUS (+) CIRCUIT OPEN
Turn the ignition off.
Disconnect the Amplifier harness connector.
Disconnect the Front Control Module C1 harness connector.
Measure the resistance of the (D55) Can B Bus (+) circuit between the Front Control Module C1 harness connector and the Amplifier harness connector.
Is the resistance below 2.0 ohms?
Yes
- Go To step 4).
- Perform BODY VERIFICATION TEST - VER 1 .
No
- Repair the Can B Bus (+) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1 .
- 4) CAN B BUS (-) CIRCUIT OPEN
Measure the resistance of the (D54) Can B Bus (-) circuit between the Front Control Module C1 harness connector and the Amplifier harness connector.
Is the resistance below 2.0 ohms?
Yes
- Replace the Amplifier in accordance with the service information.
- Perform BODY VERIFICATION TEST - VER 1 .
No
- Repair the Can B Bus (-) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1 .