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

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Turn ON the ignition, with the engine OFF.
2. Turn ON the headlamp switch.
3. Turn ON and OFF the headlamp high beam switch.
4. Turn OFF the headlamp switch.
5. Turn OFF the ignition.

Did the headlamps operate properly?

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

Go to Step 3

1. Install a scan tool.
2. Turn ON the ignition a with engine OFF.
3. Turn ON the headlamps.
4. With the scan tool, observe the headlamp switch input parameter in the dash integration module (DIM) Inputs data list.

Does the data parameter display ON?

Go to Step 4

Go to Step 5

With a scan tool, command the headlamp low beam relay ON and OFF.

Did both of the low beam headlamps turn ON and OFF?

Go to Step 16

Go to Step 6

1. Turn OFF the ignition.
2. Disconnect the headlamp switch.
3. Connect a 3-amp fused jumper between the headlamp switch ON signal circuit and the headlamp switch ground circuit.
4. Turn ON the ignition, with the engine OFF.

Does the headlamp switch input data parameter display ON?

Go to Step 17

Go to Step 14

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

Does the test lamp illuminate?

Go to Step 7

Go to Step 12

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 22

1. Turn OFF the ignition.
2. Connect a test lamp between the headlamp low beam relay control circuit and the headlamp low beam relay control side supply voltage circuit.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool command the headlamp low beam relay ON and OFF.

Did the test lamp turn ON and OFF?

Go to Step 9

Go to Step 13

1. Turn OFF the ignition.
2. Connect a 15-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.

Did both of the low beam headlamps illuminate?

Go to Step 18

Go to Step 10

1. Disconnect the inoperative low beam headlamp bulb.
2. Connect a test lamp between the inoperative low beam headlamp bulb supply voltage circuit and inoperative low beam headlamp bulb ground circuit.

Does the test lamp illuminate?

Go to Step 20

Go to Step 11

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

Did you find and correct the condition?

Go to Step 27

Go to Step 21

Test the control side supply voltage circuit of the low beam headlamp relay for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 16

Test the control circuit of the low beam headlamp relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 16

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

Did you find and correct the condition?

Go to Step 27

Go to Step 15

Test the headlamp switch on signal circuit of the headlamp switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 16

Test the Twilight Sentinel Delay Signal circuit of the DIM for a short to to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 27

Go to Step 19

Inspect for poor connections at the harness connector of 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 27

Go to Step 23

Inspect for poor connections at the low beam headlamp 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 27

Go to Step 24

Inspect for poor connections at the harness connector of the 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 27

Go to Step 25

Inspect for poor connections at the inoperative headlamp bulb. 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 27

Go to Step 26

Repair the 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 27

--

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

Did you complete the repair?

Go to Step 27

--

Replace the headlamp switch. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 27

--

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

Did you complete the replacement?

Go to Step 27

--

Important:: Perform the setup procedure for the DIM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the DIM. Refer to Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 27

--

Replace the inoperative headlamp bulb. Refer to Headlamp Bulb Replacement .

Did you complete the replacement?

Go to Step 27

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2