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

Connector End View Reference: Master Electrical Component List in Wiring Systems

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

Go to Step 2

Go to Symptoms - Lighting Systems

1. Block the wheels.
2. Disengage the parking brake.
3. Place the headlamp switch in the OFF position.
4. Turn ON the ignition, with the engine OFF.

Do the DRLs illuminate?

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

Go to Step 3

Is the brake warning indicator illuminated?

Go to Brake Warning Indicator Always On in Hydraulic Brakes

Go to Step 4

1. Turn OFF the ignition.
2. Disconnect the DRL relay.
3. Probe the DRL diode supply voltage circuit of the DRL relay with a test lamp that is connected to a good ground.
4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 5

Go to Step 11

1. Turn OFF the ignition.
2. Connect a 15-amp fused jumper wire between the DRL diode supply voltage circuit of the DRL relay and the headlamp low beam supply voltage circuit of the DRL relay.

Do the DRLs illuminate?

Go to Step 6

Go to Step 12

1. Turn ON the ignition, with the engine OFF.
2. Probe the ignition 1 voltage circuit of the DRL relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 13

Connect a test lamp between the ignition 1 voltage circuit of the DRL relay and the DRL relay control circuit of the DRL relay.

Does the test lamp illuminate?

Go to Step 9

Go to Step 8

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

Did you find and correct the condition?

Go to Step 16

Go to Step 10

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 16

Go to Step 14

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 16

Go to Step 15

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

Did you complete the repair?

Go to Step 16

--

Repair an open, high resistance or short to ground in the headlamp low beam supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

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

Did you complete the repair?

Go to Step 16

--

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

Did you complete the replacement?

Go to Step 16

--

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

Did you complete the replacement?

Go to Step 16

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3