Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool command the headlamps ON.

Do the headlamps turn ON?

Go to Step 3

Go to Step 10

1. With a scan tool observe the headlamp switch input parameter.
2. Turn the headlamp switch ON and OFF.

Does the headlamp switch input parameter turn ON and OFF?

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

Go to Step 4

1. Turn OFF the ignition.
2. Disconnect the headlamp switch.
3. Connect a fused jumper wire between the headlamp switch input circuit and a good ground.
4. Turn ON the ignition, with the engine OFF.
5. With a scan tool observe the headlamp switch input parameter.

Does the headlamp switch input parameter show ON?

Go to Step 5

Go to Step 9

1. Connect a fused jumper wire between the headlamp switch input circuit and the headlamp switch ground circuit.
2. With a scan tool observe the headlamp switch input parameter.

Does the headlamp switch input parameter show ON?

Go to Step 7

Go to Step 6

Repair the high resistance or open in the headlamp switch ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

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Inspect for poor connection at the headlamp 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 19

Go to Step 8

Replace the headlamp switch assembly. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 19

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Test the headlamp switch input circuit for high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 17

Do the park lamps turn ON?

Go to Step 11

Go to Step 16

With a scan tool command the daytime running lamps (DRL) ON.

Do the daytime running lamps turn ON?

Go to Step 13

Go to Step 12

Test the headlamp ground circuit for high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 14

Test the headlamp relay coil side feed circuit for high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 14

Inspect for poor connections at the underhood fuse block. 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 19

Go to Step 15

Replace the underhood fuse block. Refer to Underhood Fuse Block Replacement in Engine Electrical.

Did you complete the replacement?

Go to Step 19

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Test the control power feed circuit from the dash integration module to the rear fuse block for high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

Go to Step 17

Inspect for poor connections at the dash integration module (DIM). 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 19

Go to Step 18

Replace the dash integration module (DIM). Refer to Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 19

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2