U0020

U0020-CAN B BUS OFF PERFORMANCE





For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

Continuously

- Set Condition:

Whenever the CAN B Bus (+) or CAN B Bus (-) circuit is open, shorted to voltage, or shorted to ground.





Diagnostic Test

1. VERIFY DTC U0020-CAN B BUS OFF PERFORMANCE IS ACTIVE

Turn the ignition on.

With the scan tool, read Occupant Classification Module (OCM) DTCs.

Does the scan tool display active: U0020-CAN B BUS OFF PERFORMANCE?

Yes

- Go To 2

No

- If the DTC is stored, check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
- Perform ORC VERIFICATION TEST-VER 1. Occupant Restraint Controller (ORC) Verification Test

2. CHECK FOR ACTIVE CAN B BUS RELATED DTCS IN THE FRONT CONTROL MODULE (FCM)

With the scan tool, read Body Control Module (BCM) DTCs

Does the scan tool display any active CAN B BUS related DTCs?

Yes

- Diagnose and repair the DTC(s).

No

- Go To 3

3. CHECK (D55) CAN B BUS (+) CIRCUIT FOR AN OPEN





Turn the ignition off.

Disconnect the negative battery cable.

Disconnect the ORC C2 connector.

Disconnect the Body Control Module (BCM) C3 connector.

Measure the resistance of the (D55) CAN B Bus (+) circuit between the Body Control Module C3 connector and the ORC C2 connector.

Is the resistance below 2.0 ohms?

Yes

- Go To 4

No

- Repair the (D55) CAN B Bus (+) circuit for an open.
- Perform OCS VERIFICATION TEST - VER 1. Occupant Restraint Controller (ORC) Verification Test

4. CHECK (D54) CAN B BUS (-) CIRCUIT FOR AN OPEN





Measure the resistance of the (D54) CAN B Bus (-) circuit between the Body Control Module C3 connector and the ORC C2 connector.

Is the resistance below 2.0 ohms?

Yes

- Replace the ORC.
- Perform ORC VERIFICATION TEST-VER 1. Occupant Restraint Controller (ORC) Verification Test

No

- Repair the (D54) CAN B Bus (-) circuit for an open.
- Perform ORC VERIFICATION TEST-VER 1. Occupant Restraint Controller (ORC) Verification Test