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

1

Was the Lighting System Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Place the ignition switch in the OFF position.
2. Engage the parking brake.
3. Place the headlamp switch in the HEAD position.
4. Place the headlamp switch in the OFF position.
5. Turn ON the ignition, with the engine OFF.
6. Place the turn signal switch in the RH ON position.
7. Place the turn signal switch in the LH ON position.

Do the front turn signals illuminate?

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Go to Step 3

Go to Turn Signal Lamps and/or Indicators Inoperative

1. Place the turn signal switch in the OFF position.
2. Disengaged the parking brake.
3. Expose the ambient light sensor to a bright incandescent lamp.
4. Wait more than 20 seconds.

Do the front turn signal lamps illuminate?

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

Go to Step 4

Are the headlamps illuminated?

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Go to Step 5

Go to Step 6

1. Install the scan tool.
2. Expose the ambient light sensor to a bright incandescent lamp.
3. Wait more than 20 seconds.
4. With a scan tool, observe the ambient light sensor parameter in the body control module (BCM) data list.

Does the scan tool indicate that the ambient light sensor input parameter is within the specified range?

0.25-2.5 Volts

Go to Step 15

Go to Step 12

Is the park brake indicator in the instrument panel cluster (IPC) ON?

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Go to Step 7

Go to Step 8

Test for a short to ground in the park brake ON signal. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 16

Go to Step 13

1. Install the scan tool.
2. With the headlamp switch in the OFF position.
3. With a scan tool, observe the LCM Lights On Chime Input parameter in the BCM data display inputs.

Does the scan tool indicate that the Lights On Chime Input parameter is ON?

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Go to Step 15

Go to Step 9

1. Place the ignition switch in the OFF position.
2. Toggle the headlamp switch ON and OFF.
3. Place the headlamp switch in the PARK position.

Do the park lamps operate from the headlamp switch?

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Go to Step 10

Go to Park Lamps Inoperative

1. Turn headlamp switch to the OFF position.
2. Disconnect the BCM.
3. Connect a test lamp to ground and probe the exterior lamps OFF circuit of the BCM.

Does the test lamp illuminate?

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Go to Step 15

Go to Step 11

Test for an open or high resistance in the exterior lamps OFF circuit of the BCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 16

Go to Step 14

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

Did you complete the replacement?

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Go to Step 16

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Replace the park brake switch. Refer to Parking Brake Indicator Switch Replacement .

Did you complete the replacement?

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Go to Step 16

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Replace the headlamp switch. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle in Instrument Panel, Gauges, and Console.

Did you complete the replacement?

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Go to Step 16

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Important: Perform the set up procedures for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the BCM.

Did you complete the replacement?

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Go to Step 16

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2