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

DEFINITION: Automatic headlamps are inoperative.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Cover the ambient light sensor.
2. Place the headlamp switch in the AUTO position.
3. Turn ON the ignition, with the engine OFF.
4. Wait 20 seconds.

Do the headlamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

1. Disconnect the ambient light sensor.
2. With a scan tool, observe the Ambient Light Sensor parameter.

Does the scan tool indicate greater than 3.76 volts?

Go to Step 4

Go to Step 5

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

Did you find and correct the condition?

Go to Step 8

Go to Step 6

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

Did you find and correct the condition?

Go to Step 8

Go to Step 7

Replace the ambient light sensor. Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement .

Did you complete the replacement?

Go to Step 8

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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 8

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2