Diagnostic Test

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.

Is the DTC active? 

Yes 

1. Go To  2).

No 

1. The condition that caused this code to set is not present at this time. 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.
2. Perform BODY VERIFICATION TEST - VER 1 .

With the scan tool, read Front Control Module DTCs.

Does the scan tool display the U0019-CAN B BUS DTC? 

Yes 

1. Refer to the symptom list for problems related to Communication. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING)

No 

1. Go to  3).

Fig 1: Checking CAN B BUS (+) Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the negative battery cable.

Disconnect the Instrument Cluster C3 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 Instrument Cluster C3 harness connector.

Is the resistance below 2.0 ohms? 

Yes 

1. Go To  4).

No 

1. Repair the Can B Bus (+) circuit for an open.
2. Perform BODY VERIFICATION TEST - VER 1 .

Fig 2: Checking CAN B BUS (-) Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the (D54) Can B Bus (-) circuit between the Front Control Module C1 harness connector and the Instrument Cluster C3 harness connector.

Is the resistance below 2.0 ohms? 

Yes 

1. Replace the Instrument Cluster in accordance with the Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .

No 

1. Repair the Can B Bus (-) circuit for an open.
2. Perform BODY VERIFICATION TEST - VER 1 .