Antilock Brake System (ABS): 1020

1020 - CAN BUS COMMUNICATION GENERAL MALFUNCTION





When Monitored and Set Condition

- When Monitored: With the ignition on.
- Set Condition: CAN Bus communication failure between the Controller Antilock Brake (CAB) and the CAN Bus network.





For a complete Antilock Brake System (ABS) Circuit Diagram Refer to BRAKES - SCHEMATICS And DIAGRAMS Schematics And Diagrams.


Diagnostic Test

1. MEASURE THE RESISTANCE OF THE CAN C BUS (+) CIRCUIT





Turn the ignition off.

Disconnect the CAB harness connector.

Disconnect the harness connectors of the other modules on the CAN Bus network.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the CAN C Bus (+) circuit from the CAB harness connector to the harness connectors of the other modules on the CAN Bus network.

Is the resistance below 1.0 ohm?

Yes

- Go to 2

No

- Repair the CAN C Bus (+) circuit for an open.
- Perform ABS Verification Test. ABS Verification Test


2. MEASURE THE RESISTANCE OF THE CAN C (-) BUS CIRCUIT





With the ignition off.

Measure the resistance of the CAN C Bus (-) circuit from the CAB harness connector to the harness connectors of the other modules on the CAN Bus network.

Is the resistance below 1.0 ohm?

Yes

- Replace the Controller Antilock Brake (CAB) Module.
- Perform ABS Verification Test. ABS Verification Test

No

- Repair the CAN C Bus (-) circuit for an open.
- Perform ABS Verification Test. ABS Verification Test