GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

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

1

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

Go to Step 2

Go to Symptoms - Lighting Systems

2

Verify that the daytime running lamps are on with the park brake applied.

Does the system operate normally?

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

Go to Step 3

3

  1. Disconnect the DRL control module connector
  2. Test for high resistance between the DRL control module connector cavity 14 to chassis ground with the brake applied.

Is a high resistance condition present?

Go to Step 4

Go to Step 5

4

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

Is the replacement complete?

Go to Step 8

--

5

  1. Disconnect the parking brake switch connector.
  2. Disconnect the DRL control module connector.
  3. Test for an open between the DRL control module connector cavity 14 and the parking brake connector cavity.

Is an open condition present?

Go to Step 7

Go to Step 6

6

Locate and repair the open in the DRL relay control circuit between the brake switch connector and the DRL control module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 8

--

7

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

Is the replacement complete?

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3