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

1

Was the Lighting System Diagnostic System Check performed?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Turn ON the ignition, with the engine OFF.
2. Place the headlamp switch in the HEADLAMP position.
3. Place the headlamp dimmer switch in the HIGH BEAM position.

Do the high beam headlamps operate properly?

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

Go to Step 3

Place the headlamp dimmer switch in the LOW BEAM position.

Do the low beam headlamps operate properly?

Go to Step 4

Go to Headlamps Inoperative - Low Beams

Place the headlamp dimmer switch in the HIGH BEAM position.

Are both of the high beam headlamps inoperative?

Go to Step 7

Go to Step 5

1. Disconnect the inoperative high beam headlamp.
2. Connect a test lamp between the supply voltage circuit of the high beam headlamp and a good ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 25

Connect a test lamp between the supply voltage circuit of the high beam headlamp and the ground circuit of the high beam headlamp.

Does the test lamp illuminate?

Go to Step 18

Go to Step 13

With a scan tool, observe the High Beam Switch parameter in the Instrument Cluster (IPC) inputs data list.

Does the scan tool indicate that the High Beam Switch parameter is on?

Go to Step 9

Go to Step 8

1. Disconnect the headlamp dimmer switch.
2. Connect a 10 amp fused jumper between the battery positive voltage circuit of the headlamp dimmer switch and the high beam signal circuit of the headlamp dimmer switch.
3. With a scan tool, observe the High Beam Switch parameter in the Instrument Cluster (IPC) inputs data list.

Does the scan tool indicate that the High Beam Switch parameter is on?

Go to Step 20

Go to Step 14

1. Place the headlamp dimmer switch in the LOW BEAM position.
2. With a scan tool, command the HIGH/LOW BEAM HEADLAMP relay ON and OFF.

Do you hear a click when you command the HIGH/LOW BEAM HEADLAMP relay ON and OFF?

Go to Step 12

Go to Step 10

1. Turn OFF the ignition.
2. Disconnect the HIGH/LOW BEAM HEADLAMP relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the battery positive voltage circuit of the HIGH/LOW BEAM HEADLAMP relay coil and a good ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 24

1. Connect a test lamp between the battery positive voltage circuit of the HIGH/LOW BEAM HEADLAMP relay coil and the control circuit of the HIGH/LOW BEAM HEADLAMP relay.
2. With a scan tool, command the HIGH/LOW BEAM HEADLAMP relay ON.

Does the test lamp illuminate?

Go to Step 17

Go to Step 16

1. Turn OFF the ignition.
2. Disconnect the HIGH/LOW BEAM HEADLAMP relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a 20 amp fused jumper between the headlamp supply voltage circuit of the HIGH/LOW BEAM HEADLAMP relay switch and the supply voltage circuit of the high beam headlamps.

Do the high beam headlamps illuminate?

Go to Step 17

Go to Step 23

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

Did you find and correct the condition?

Go to Step 32

Go to Step 22

Test for an open or high resistance in the battery positive voltage circuit of the headlamp dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 32

Go to Step 15

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

Did you find and correct the condition?

Go to Step 32

Go to Step 19

Test for an open or high resistance in the control circuit of the HIGH/LOW BEAM HEADLAMP relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 32

Go to Step 21

Inspect for poor connections at the HIGH/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 32

Go to Step 27

Inspect for poor connections at the inoperative high beam 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 32

Go to Step 28

Inspect for poor connections at the harness connector of the Instrument Cluster (IPC). 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 32

Go to Step 26

Inspect for poor connections at the harness connector of the headlamp dimmer 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 32

Go to Step 31

Inspect for poor connections at the harness connector of the Body Control Module (BCM). 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 32

Go to Step 29

Inspect for poor connections at 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 32

Go to Step 30

Repair an open or high resistance in the supply voltage circuit of the high beam headlamps. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 32

--

Repair an open or high resistance in the battery positive voltage circuit of the HIGH/LOW BEAM HEADLAMP relay coil. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 32

--

Repair an open or short to ground in the supply voltage circuit of the inoperative high beam headlamp. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 32

--

Replace the Instrument Cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 32

--

Replace the HIGH/LOW BEAM HEADLAMP relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 32

--

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

Did you complete the replacement?

Go to Step 32

--

Replace the Body Control Module (BCM). Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 32

--

Replace the DRL relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 32

--

Replace the headlamp dimmer switch. Refer to Headlamp Dimmer Switch Replacement - On Vehicle in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 32

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2