Schematic Reference: Headlights/Daytime Running Lights (DRL) 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. Place the headlamp switch in the ON position.
2. Place the dimmer switch in the low beam position.

Do the low beam headlamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Is only one low beam headlamp inoperative?

Go to Step 4

Go to Step 5

Test the headlamp low beam supply voltage and ground circuits for 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 16

Go to Step 9

1. Place the headlamp switch in the HEAD position.
2. Place the headlamp dimmer switch in the low beam position.
3. With a scan tool, monitor the Low Beam Relay Command data parameter in the body control module (BCM) data list.

Does the scan tool display On?

Go to Step 14

Go to Step 6

Disconnect the multifunction switch.

Do the low beam headlamps illuminate?

Go to Step 7

Go to Step 11

Test the headlamp dimmer switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct a condition?

Go to Step 16

Go to Step 8

Test the headlamp switch flash to pass signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct a condition?

Go to Step 16

Go to Step 10

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

Did you find and correct the condition?

Go to Step 16

Go to Step 12

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

Did you find and correct the condition?

Go to Step 16

Go to Step 15

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 16

Go to Step 13

Replace the inoperative bulb. Refer to Headlamp Bulb Replacement.

Did you complete the replacement?

Go to Step 16

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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 16

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Replace the low beam relay. Refer to Relay Replacement.

Did you complete the replacement?

Go to Step 16

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Replace the headlamp dimmer switch. Refer to Turn Signal Multifunction Switch Replacement.

Did you complete the repair?

Go to Step 16

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3