Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

1. Place the ignition switch in the OFF position.
2. Engage the park brake.
3. Place the headlamp switch in the OFF position.
4. Turn ON the ignition, with the engine OFF.
5. Place the turn signal switch in the RH ON position.
6. Place the turn signal switch in the LH ON position.

Do the front turn signals operate properly?

Go to Step 3

Go to Turn Signal Lamps and/or Indicators Inoperative

1. Release the park brake.
2. Apply a bright incandescent light to the twilight sensor.
3. Place the turn signal switch in the OFF position.

Do the front turn signals lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

Is the park brake indicator in the instrument panel cluster (IPC) ON?

Go to Brake Warning Indicator Always On in Hydraulic Brakes

Go to Step 5

1. Install a scan tool.
2. Turn the ignition to ON position.
3. Apply a bright incandescent light to the twilight sensor.
4. With a scan tool, observe the Ambient Light Sensor parameter in the HVAC data list.

Does the scan tool indicate that the DRL Ambient Light Sensor parameter is between 50-60 counts?

Go to Step 8

Go to Step 6

Test for a poor connection or an open in the twilight sensor signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

Replace the sunload sensor. Refer to Sun Load Sensor Replacement in HVAC.

Did you complete the replacement?

Go to Step 9

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Important: Perform the setup procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.

Replace the BCM. Refer to Body Control Module Replacement in Computer/Integrating Systems.

Did you complete the replacement?

Go to Step 9

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2