Initial Inspection and Diagnostic Overview

INSPECTION AND VERIFICATION

1. Verify the customer concern.

Visual Inspection Chart:

2. Visually inspect for obvious signs of mechanical or electrical damage.
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

NOTE: Make sure the headlamp switch is in the OFF position.

4. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
- check that the program card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch position.

5. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
6. Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
- SCP+, SCP-, ISO or UBP circuit fault; all electronic control units no response/not equipped, refer to Module Communications Network (Information Bus).
- No response/not equipped for REM, refer to Module Communications Network (Information Bus).
- System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the REM.

7. If the DTCs retrieved are related to the concern, go to the Rear Electronic Module (REM) Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures
8. If multiple symptoms exist, check the Switched System Power (SSP) Relay Index before proceeding to the next step. Refer to Headlamps.
9. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures

NOTE: For a complete master list of DTCs, refer to Module Communications Network (Information Bus).