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

Did you perform the Lighting Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

Verify the fault is present.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

1. Block the drive wheels.
2. Turn ON the ignition with the engine OFF.
3. Place the gear selection in the DRIVE position.
4. Ensure the headlamp switch is in the AUTO position.
5. Ensure the parking brake is released.
6. Ensure the ambient light sensor is not covered or has no obstruction to daylight.

Did you find and correct the condition?

Go to Step 15

Go to Step 4

Test the DRL supply voltage circuit for high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 5

1. Remove the DRL relay.
2. Connect a fused jumper wire between the battery positive voltage circuit and the DRL supply voltage circuit on the switch side of the relay connector.

Do the DRL illuminate?

Go to Step 6

Go to Step 8

1. Remove the fused jumper wire.
2. Connect a test lamp between the battery positive voltage circuit and the DRL relay control circuit of the DRL relay.
3. Turn ON the ignition, with the engine OFF.
4. With the scan tool, command the DRL relay on.

Does the test lamp illuminate?

Go to Step 10

Go to Step 7

Test the DRL relay control circuit between the engine wiring harness junction block and the body control module (BCM) for high resistance or an open. Refer Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

Test the ground circuit of the lamp(s) for high resistance or an open.

Did you find and correct the condition?

Go to Step 15

Go to Step 9

Inspect for poor connections at the harness connector of the lamp(s). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

Inspect for poor connections at the harness connector of the DRL relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

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

Did you find and correct the condition?

Go to Step 15

Go to Step 14

Replace the lamp(s) as necessary. Refer to Parking and Turn Signal Lamp Replacement .

Did you complete the replacement?

Go to Step 15

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Replace the DRL relay. Refer to Daytime Running Lamps (DRL) Relay Replacement .

Did you complete the replacement?

Go to Step 15

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Important: Perform the setup procedure for the BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 15

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3