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

Did you review the daytime running lamps (DRL) operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

1. Turn ON the ignition, with the engine OFF.
2. Turn OFF the headlamps.
3. Ensure the park brake is released.

Does the DRL system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

Turn ON the low beam headlamps.

Do the low beam headlamps operate correctly?

Go to Step 4

Go to Headlamps Inoperative - Low Beams

Is the DRL indicator inoperative while the DRL are illuminated?

Go to Daytime Running Lamps (DRL) Indicator Inoperative

Go to Step 5

Is the DRL indicator illuminated while the DRL are inoperative?

Go to Step 6

Go to Step 12

Test the DRL relay control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 7

Test the ignition 1 voltage circuit of the DRL relay for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 8

Test the ignition 1 voltage circuit of the DRL relay for high resistance, an open, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 9

Test the battery positive voltage circuit of the DRL diode for high resistance, an open, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 10

Connect a fused jumper wire between the battery positive voltage circuit and the DRL diode supply voltage circuit of the DRL diode.

Does the DRL illuminate?

Go to Step 16

Go to Step 11

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

Did you find and correct the condition?

Go to Step 25

Go to Step 17

1. Disconnect the DRL control module connector.
2. Turn ON the ignition.
3. Connect a test lamp between the ignition 1 voltage circuit of the DRL control module and ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 20

Test the ground circuit of the DRL control module for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 14

1. Disconnect the park brake switch connector.
2. Test the park brake switch for continuity to ground without the park brake being applied.

Is continuity to ground present across the parking brake switch?

Go to Step 18

Go to Step 15

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

Did you find and correct the condition?

Go to Step 25

Go to Step 19

Inspect for poor connections at the harness connector of the DRL diode. 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 25

Go to Step 24

Inspect for poor connections at the harness connector of the DRL 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 25

Go to Step 21

Inspect for poor connections at the harness connector of the park brake 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 25

Go to Step 22

Inspect for poor connections at the harness connector of the DRL control module. 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 25

Go to Step 23

Repair the DRL relay ignition supply circuit for an open. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

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Replace the DRL relay.

Did you complete the replacement?

Go to Step 25

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

Did you complete the replacement?

Go to Step 25

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

Did you complete the replacement?

Go to Step 25

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Replace the DRL diode. Refer to Daytime Running Lamp (DRL) Diode Replacement .

Did you complete the replacement?

Go to Step 25

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3