Inspection and Verification

Daytime Running Lamps (DRL)

Inspection and Verification

1. Verify the customer concern.

2. Visually inspect the following for obvious signs of electrical damage.

Visual Inspection Chart






3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

4. NOTE: Make sure to use the latest scan tool software release.

If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).


5. NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms power and ground from the DLC (Data Link Connector) are provided to the VCM (Vehicle Communication Module).

If the scan tool does not communicate with the VCM (Vehicle Communication Module) :

- Check the VCM (Vehicle Communication Module) connection to the vehicle.

- Check the scan tool connection to the VCM (Vehicle Communication Module).

- Refer to - No Power To The Scan Tool, to diagnose no power to the scan tool.


6. If the scan tool does not communicate with the vehicle:
- Verify the ignition is in the ON position.

- The air bag warning indicator prove-out (other indicators may not prove ignition ON) confirm ignition ON. If the ignition does not turn on, refer to Steering Column to diagnose no power in RUN.

- Verify the scan tool operation with a known good vehicle.

- to diagnose no response from the PCM.


7. Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Information Bus.

- If the network test passes, retrieve and record the continuous memory DTCs.


8. Check the Smart Junction Box (SJB) and make sure the Daytime Running Lamps (DRL) configuration is enabled.

9. If DTCs are retrieved, refer to the Diagnostic Trouble Code (DTC) Chart in Body Control Systems. Body Control Systems/ Body Control Module

10. If no DTCs are retrieved, GO to Symptom Chart. Symptom Related Diagnostic Procedures