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

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

1. Turn ON the ignition, with the engine OFF.
2. Turn ON the headlamp switch.
3. Place the headlamp dimmer switch in the low beam position.

Do the low beam headlamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Are both low beam headlamps inoperative?

Go to Step 4

Go to Step 9

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Turn ON the low beam headlamps.
4. With the scan tool, observe the Headlamp ON Switch parameter in the body control module (BCM) exterior lamps data list.

Does the Headlamp ON Switch parameter display ACTIVE?

Go to Step 6

Go to Step 5

1. Turn OFF the ignition.
2. Disconnect the turn signal/multifunction switch C3 harness connector.
3. Connect a 3-amp fused jumper between the headlamp ON signal circuit at the turn signal/multifunction switch C3 harness connector and the ground circuit of the turn signal/multifunction switch at the C3 harness connector.
4. Turn ON the ignition, with the engine OFF.
5. With the scan tool, observe the Headlamp ON Switch parameter in the BCM exterior lamps data list.

Does the Headlamp ON Switch parameter display ACTIVE?

Go to Step 14

Go to Step 12

1. Turn OFF the ignition.
2. Disconnect the headlamp LOW BEAM relay located in the underhood fuse block. Refer to Relay Replacement in Wiring Systems.
3. Connect a test lamp between the headlamp low beam relay control side supply voltage circuit and the headlamp low beam relay control circuit.
4. Turn ON the ignition, with the engine OFF.
5. Turn ON the low beam headlamps.

Does the test lamp illuminate?

Go to Step 7

Go to Step 11

Connect a test lamp between the headlamp low beam relay switch side supply voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 19

1. Turn OFF the ignition.
2. Connect a 40-amp fused jumper between the headlamp low beam relay switch side supply voltage circuit and the headlamp low beam supply voltage circuit.
3. Turn ON the ignition, with the engine OFF.

Do both low beam headlamps illuminate?

Go to Step 15

Go to Step 9

1. Turn OFF the ignition.
2. Disconnect the inoperative low beam headlamp.
3. Connect a test lamp between the low beam headlamp supply voltage circuit and the ground circuit of the inoperative low beam headlamp.
4. Turn ON the ignition, with the engine OFF.
5. Turn ON the low beam headlamps.

Does the test lamp illuminate?

Go to Step 17

Go to Step 10

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

Did you find and correct the condition?

Go to Step 24

Go to Step 18

Test the headlamp low beam relay control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 16

Test the turn signal/multifunction switch ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 13

Test the headlamp switch headlamp ON signal circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 24

Go to Step 16

Inspect for poor connections at the C3 harness connector of the turn signal/multifunction switch. 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 24

Go to Step 20

Inspect for poor connections at the headlamp low beam 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 24

Go to Step 21

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 24

Go to Step 22

Inspect for poor connections at the harness connector of the inoperative low beam high intensity discharge (HID) headlamp. 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 24

Go to Step 23

Locate and repair an open or high resistance in the headlamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

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Locate and repair an open or high resistance in the switch side supply voltage circuit of the headlamp low beam relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 24

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Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 24

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Replace the headlamp low beam relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 24

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Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 24

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Important: Verify that the headlamp ballast connector retaining clip is fully installed.

Replace the inoperative HID headlamp ballast. Refer to High Intensity Discharge Headlamp Ballast Replacement .

Did you complete the replacement?

Go to Step 24

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2