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

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

1. Turn OFF the ignition.
2. Place the headlamp switch in the HEAD position.

Do the headlamps illuminate?

Go to Step 3

Go to Low and High Beams Headlamps Inoperative

1. Place the headlamp switch in the OFF position.
2. Verify the parking brake is disengaged.
3. Cover the ambient light sensor.
4. Turn ON the ignition, with the engine OFF.

Do the headlamps illuminate?

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

Go to Step 4

Are the park lamps illuminated?

Go to Step 7

Go to Step 5

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

Go to Brake Warning Indicator Always On in Hydraulic Brakes

Go to Step 6

Are the DRL lamps illuminated?

Go to Step 13

Go to Step 10

1. Turn OFF the ignition.
2. Disconnect the daytime running lamps (DRL) control module.
3. Turn ON the ignition, with the engine OFF.
4. Probe the ignition 3 voltage circuit of the DRL control module connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 18

With a test lamp that is connected to ground, probe the battery positive voltage circuit of the DRL control module connector that is fed by the HEADLAMP circuit breaker.

Does the test lamp illuminate?

Go to Step 9

Go to Step 20

1. Turn headlamp switch to the HEAD position.
2. Probe the headlamp supply voltage circuit of the DRL control module connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 21

1. Turn OFF the ignition.
2. Disconnect the daytime running lamps (DRL) control module.
3. Turn ON the ignition, with the engine OFF.
4. Probe the ignition 1 voltage circuit of the DRL control module connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 16

Probe the ground circuit of the DRL control module connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 12

Go to Step 19

Connect a fused jumper between the parkbrake switch signal circuit of the DRL control module and ground. Refer to Circuit Testing in Wiring Systems.

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

Go to Step 15

Go to Step 23

1. Turn OFF the ignition.
2. Disconnect the daytime running lamps (DRL) control module.
3. Turn ON the ignition, with the engine OFF.
4. With a test lamp that is connected to ground, probe the battery positive voltage circuit of the DRL control module connector that is fed by the PARK LP fuse.

Does the test lamp illuminate?

Go to Step 14

Go to Step 22

Disconnect the ambient light sensor and operate the system . Refer to Daytime Running Lamp (DRL) Ambient Light Sensor Replacement .

Do the automatic headlamps illuminate?

Go to Step 24

Go to Step 15

Inspect for poor connections at the daytime running lamps (DRL) control module Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 25

Test for an open or high resistance in the ignition 1 voltage circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 17

Repair a short to ground in the ignition 1 voltage circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the ignition 3 voltage circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the ground circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the battery positive voltage circuit of the DRL control module connector that is fed by the HEADLAMP circuit breaker. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the headlamp supply voltage circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the battery positive voltage circuit of the DRL control module connector that is fed by the PARK LP fuse. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

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Repair an open or high resistance in the parkbrake switch signal circuit of the DRL control module connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 26

--

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

Did you complete the replacement?

Go to Step 26

--

Replace the daytime running lamps (DRL) control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Did you complete the replacement?

Go to Step 26

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2