Can B Bus (-) Circuit Failure

When Monitored
Continuous.

Set Condition
CAN B Bus (-) communication failure between the Body Control Module (BCM) and the Central Locking Pump/Security System Module (CLP/SSM).

POSSIBLE CAUSES
- CAN b bus (-) circuit shorted to voltage
- CAN b bus (-) circuit shorted to ground
- CAN b bus (-) circuit open
- Central locking pump/security system module

Diagnostic Test




1. MEASURE THE RESISTANCE OF THE CAN B BUS (-) CIRCUIT

Turn the ignition off.
Disconnect the BCM harness connector.
Disconnect the CLP/SSM harness connector.

NOTE: Check connectors - Clean/repair as necessary. Measure the resistance of the CAN B Bus (-) circuit from the BCM harness connector to the CLP/SSM harness connector.

Q: Is the resistance below 1.0 ohm?

YES: Go to 2
NO: Repair the CAN B Bus (-) circuit for an open. Perform VTSS VERIFICATION TEST. VTSS Verification Test




2. MEASURE THE VOLTAGE OF THE CAN B BUS (-) CIRCUIT

Turn the ignition on.

Measure the voltage of the CAN B Bus (-) circuit at the CLP/SSM harness connector.

Q: Is voltage present?

YES: Repair the CAN B Bus (-) circuit for a short to voltage. Perform VTSS VERIFICATION TEST. VTSS Verification Test
NO: Go to 3




3. MEASURE THE RESISTANCE OF THE CAN B BUS (-) CIRCUIT

Turn the ignition off.

Measure the resistance between ground and the CAN B Bus (-) circuit at the CLP/SSM harness connector.

Q: Is the resistance below 10K ohms?

YES: Repair the CAN B Bus (-) circuit for a short to ground. Perform VTSS VERIFICATION TEST. VTSS Verification Test
NO: Replace the Central Locking Pump/Security System Module. Perform VTSS VERIFICATION TEST. VTSS Verification Test