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

Connector End View Reference: Master Electrical Component List

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Place the vehicle in the ON position.
2. Disengage the park brake.
3. Place the vehicle in drive.
4. Expose the ambient light sensor to a bright incandescent lamp.

Do the low beam headlamps illuminate at reduced intensity?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

1. Install a scan tool.
2. Expose the ambient light sensor to a bright incandescent lamp.
3. With a scan tool, observe the Headlamp/DRL Output parameter in the body control module (BCM) data list.

Does the scan tool display DRL?

Go to Step 4

Go to Step 5

Replace the headlamp module in the underhood fuse block. Refer to Relay Replacement .

Did you complete the repair?

Go to Step 6

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Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 6

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3