Diagnostic Test

CHECK FOR ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Test complete. The condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (W110) FRONT WIPER SWITCH MUX CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Right Multifunction Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (W110) Front Wiper Switch MUX circuit at the Right Multifunction Switch harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (W110) Front Wiper Switch MUX circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (W110) FRONT WIPER SWITCH MUX CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the BCM C8 harness connector.
3. Measure the resistance of the (W110) Front Wiper Switch MUX circuit between the Right Multifunction Switch harness connector and the BCM C8 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the open in the (W110) Front Wiper Switch MUX circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Z407) GROUND CIRCUIT FOR AN OPEN
1. Measure the resistance of the (Z407) Ground circuit between the Right Multifunction Switch harness connector and the BCM C8 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (Z407) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE BCM FOR CORRECT OPERATION
1. Turn the ignition off.
2. Connect the BCM C8 harness connector.
3. Connect a jumper wire between the (W110) Front Wiper Switch MUX circuit and the (Z407) Ground circuit at the Right Multifunction Switch harness connector.
4. Turn the ignition on.
5. With the scan tool, view the Front Wiper Switch in BCM Data.
  Does the Front Wiper Switch display On?
  
  Yes
  - Replace the Right Multifunction Switch in accordance with the Service Information. Refer to SWITCH, MULTIFUNCTION, RIGHT, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .