Diagnostic Test

1) MEASURE WIPER SWITCH MUX CIRCUIT VOLTAGE
NOTE: If any BCM DTCs are set, diagnose them first before continuing.

Fig 1: Measuring Wiper Switch Mux Circuit Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the BCM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage of the Wiper Switch Mux circuit at cavity 65 of the BCM harness connector.

Is voltage present?

Yes
1. Go to step 2).
No
1. Replace the Body Control Module. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/BODY CONTROL/CENTRAL TIMER MODULE - REMOVAL) .
2. Perform BODY VERIFICATION TEST .
2) MEASURE MULTI-FUNCTION SWITCH VOLTAGE

Fig 2: Measuring Multi-Function Switch Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Multi-Function Switch harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage of the Wiper Switch Mux circuit at cavity 7 of the Multi-Function Switch harness connector.

Is voltage present?

Yes
1. Repair the Wiper Switch Mux circuit for a short to voltage.
2. Perform BODY VERIFICATION TEST .
No
1. Replace the Multi-Function Switch. (Refer to ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-FUNCTION SWITCH - REMOVAL) .
2. Perform BODY VERIFICATION TEST .