GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

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

Connector End View Reference: Lighting Systems Connector End Views or Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Place the gear selector in the PARK position.

Do the daytime running lamps remain illuminated?

Go to Step 3

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

3

With a scan tool, observe the Daytime Running Lamp parameter in the Dash Integration Module (DIM) outputs data list.

Does the scan tool indicate that the Daytime Running Lamp parameter is OFF?

Go to Step 4

Go to Step 8

4

  1. Turn OFF the ignition.
  2. Disconnect the daytime running lamp (DRL) relay.
  3. Turn ON the ignition, with the engine OFF.

Did the DRL headlamps turn OFF?

Go to Step 5

Go to Step 9

5

Connect a test lamp between the control circuit of the DRL relay to the battery positive voltage circuit of the DRL relay coil.

Does the test lamp illuminate?

Go to Step 6

Go to Step 7

6

Test for a short to ground in the DRL relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 8

7

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 12

Go to Step 10

8

Inspect for poor connections at 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 12

Go to Step 11

9

Repair the short to voltage in the DRL supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

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10

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

Did you complete the replacement?

Go to Step 12

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11

Replace the DIM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2