Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Carefully supply sufficient light to the ambient light sensor.
2. Start the engine.
3. With the headlamps in the AUTO position, toggle the daytime running lamps (DRL) defeat switch several times.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

With a scan tool, command the DRL ON and OFF several times.

Do the DRL operate as expected?

Go to Step 4

Go to Step 6

Test the DRL On/Off signal circuit of the body control module (BCM) for a high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 5

Inspect for poor connections at the harness connector of the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 7

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 9

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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 9

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3