GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

DEFINITION: Front fog lamps are always on, or the front fog lamps are on with the fog lamp switch in the OFF position and park lamps on.

1

Did you perform the Diagnostic System Check - Lighting Systems?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the headlamp switch to the PARK position on the headlamp/instrument panel (IP) dimmer switch.
  2. Turn the fog lamp switch to the OFF position.
  3. Use a test lamp in order to backprobe the rear window wiper/washer and multi-function switch connector C3 terminal E to ground.

Did the test lamp light?

Go to Step 3

Go to Step 6

3

  1. Disconnect the rear window wiper/washer and multi-function switch connector C3.
  2. Use a test lamp in order to backprobe between the rear window wiper/washer and multi-function switch connector C3 terminal E and ground.

Did the test lamp light?

Go to Step 4

Go to Step 5

4

  1. Disconnect the underhood accessory junction block connector C2.
  2. Use a test lamp in order to probe the underhood accessory junction block connector C2 terminal E5 and ground.

Did the test lamp light?

Go to Step 10

Go to Step 9

5

  1. Replace the rear window wiper/washer and multi-function switch. Refer to Multifunction Switch Assembly Replacement - Instrument Panel
  2. Inspect the system.

Is the repair complete?

Go to Step 12

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6

Remove the fog lamp relay.

Did the fog lamps turn off?

Go to Step 11

Go to Step 7

7

Disconnect the underhood accessory junction block connector C3.

Does one fog lamp stay on and the other fog lamp turn off?

Go to Step 8

Go to Step 9

8

Repair a short to B+ in CKT 34 for the affected fog lamp.

Is the repair complete?

Go to Step 12

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9

Replace the underhood accessory junction block. Refer to Relay/Fuse Center Replacement

Is the repair complete?

Go to Step 12

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10

Repair a short to B+ in CKT 317.

Is the repair complete?

Go to Step 12

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11

Replace the fog lamp relay.

Is the repair complete?

Go to Step 12

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12

  1. Connect all connectors that were previously disconnected.
  2. Verify that the fog lamps operate properly.

Do the fog lamps operate properly?

System OK

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