GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Turn the Headlights Dimmer Switch to the HI position and observe the Headlamps.

Did the highbeam filaments light?

--

Go to Step 2

Go to Step 5

2

  1. Turn the Headlamp Dimmer Switch to the LOW position.
  2. Remove the Daytime Running Light (DRL) Relay.
  3. Connect a test lamp between terminal D4 in the Daytime Running Light relay socket and chassis ground

Did the test lamp light?

--

Go to Step 3

Go to Step 4

3

  1. Disconnect the Right Hand Headlamp harness connector.
  2. Connect a jumper between terminal C in the Right Hand Headlamp harness connector and chassis ground.
  3. Use a J 39200 between terminal D3 in the DRL Relay socket and chassis ground.

Does the DMM indicate continuity?

--

Go to Step 9

Go to Step 10

4

  1. Turn the Headlamp Dimmer Switch to the LOW position.
  2. Disconnect the Headlamp Dimmer Switch harness connector.
  3. Use a J 39200 between terminal C and terminal D in the Headlamp Dimmer Switch connector.

Does the DMM indicate continuity?

--

Go to Step  11

Go to Step  12

5

Inspect the DRL for proper operation

Does the DRL operate properly?

--

Go to Step  6

Go to Step 7

6

  1. Disconnect the Headlamp Dimmer Switch harness connector.
  2. Disconnect the Headlamp Switch harness connector.
  3. Use a J 39200 between terminal D in the Headlamp Switch harness connector and terminal D in the Headlamp Dimmer Switch harness connector.

Does the DMM indicate continiuity?

--

Go to Step  13

Go to Step 14

7

  1. Disconnect the Headlamp Switch harness connector.
  2. Connect a test lamp between terminal C in the Headlamp Switch harness connector and chassis ground.

Did the test lamp light?

--

Go to Step 8

Go to Step 15

8

Use a J 39200 between terminal B and terminal C in the Headlamp Switch

Does the DMM indicate continuity?

--

Go to Step 16

Go to Step 14

9

Replace the Daytime Running Light Relay.

Is the repair complete?

--

System OK

--

10

Locate and repair the open in CKT 12 (TAN) between terminal D3 in the Daytime Running Light Relay socket and terminal C in the Right Hand Headlamp harness connector.

Is the repair complete?

--

System OK

--

11

Locate and repair the open in CKT 544 (PPL) between terminal C in the Headlamp Dimmer Switch harness connector and terminal D4 in the Daytime Running Lights Relay socket.

Is the repair complete?

--

System OK

--

12

Replace the Headlamp Dimmer Switch.

Is the repair complete?

--

System OK

--

13

Locate and repair the open in CKT 10 (YEL) between terminal D in the Headlamp Switch harness connector and terminal D in the Headlamp Dimmer Switch harness connector.

Is the repair complete?

--

System OK

--

14

Replace the Headlamp Switch.

Is the repair complete?

--

System OK

--

15

Locate and repair the open in CKT 742 (RED) between terminal C in the Headlamp Switch harness connector and terminal A4 at the Headlamp Switch MaxiFuse® .

Is the repair complete?

--

System OK

--

16

Locate and repair the open in CKT 150 (BLK) between S105 and G102.

Is the repair complete?

--

System OK

--