GM Service Manual Online
For 1990-2009 cars only

Headlamps, Daytime Running Lamps (DRL) On with Headlamp Switch On Domestic

Step

Action

Value(s)

Yes

No

1

Review the daytime running lamp (DRL) operation and perform the necessary inspections.

Did you complete the system review and inspection?

--

Go to Step 2

Go to Symptoms

2

Attempt to operate the DRL with the headlamps on.

Does the system operate with the headlamps on?

--

Go to Step 3

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

3

  1. Remove the DRL relay.
  2. Disconnect the DRL control module.
  3. Test for a short to ground in CKT 592 (LT GRN/BLK) which connects the DRL control module to the DRL relay coil.
  4. If a short to ground was located, repair it.

Did you locate and repair a short to ground?

--

Go to Step 5

Go to Step 4

4

Replace the daytime running lamp control module.

Is the repair complete?

--

Go to Step 5

--

5

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Headlamps, Daytime Running Lamps (DRL) On with Headlamp Switch On Export

Step

Action

Value(s)

Yes

No

1

Review the daytime running lamp (DRL) operation and perform the necessary inspections.

Did you complete the system review and inspection?

--

Go to Step 2

Go to Symptoms

2

Attempt to operate the DRL with the headlamps on.

Does the system operate with the headlamps on?

--

Go to Step 3

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

3

  1. Remove the DRL relay.
  2. Disconnect the DRL control module.
  3. Test for a short to ground in CKT 592 (LT GRN/BLK) which connects the DRL control module to the DRL relay coil.
  4. If a short to ground was located, repair it.

Did you locate and repair a short to ground?

--

Go to Step 7

Go to Step 4

4

  1. Disconnect the DRL control module.
  2. Turn on the parklamps.
  3. Measure the voltage at cavity D of the DRL control module connector.

Was the measurement equal to battery voltage?

B+

Go to Step 6

Go to Step 5

5

Repair the open CKT 9 (BRN) between the DRL control module and splice S225.

Did you complete the repair?

--

Go to Step 7

--

6

Replace the daytime running lamp control module.

Did you complete the repair?

--

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3