Diagnostic Test

1) Open CAN B Bus (+) circuit

Fig 1: Checking CAN B BUS (+) Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Power Top Control Module (PTCM) C1 harness connector.

Disconnect the Central Locking Pump/Security System Module (CLP/SSM) harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the CAN B Bus (+) circuit from the PTCM C1 harness connector to the CLP/SSM harness connector.

Is the resistance below 5.0 ohm?

Yes
1. Go To step 2).
No
1. Repair the PTCM CAN B Bus (+) circuit for an open.
2. Perform POWER TOP VERIFICATION TEST .
2) Open CAN B Bus (-) circuit

Fig 2: Checking CAN B BUS (-) Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the CAN B Bus (-) circuit from the PTCM C1 harness connector to the CLP/SSM harness connector.

Is the resistance below 5.0 ohm?

Yes
1. Replace the Power Top Control Module. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/POWER TOP CONTROL MODULE - REMOVAL)
2. Perform POWER TOP VERIFICATION TEST .
No
1. Repair the PTCM CAN B Bus (-) circuit for an open.
2. Perform POWER TOP VERIFICATION TEST .