GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Fog Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring 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. Turn the headlamp switch to the HEAD position.
  3. Turn the headlamp dimmer switch to the LOW beam position.
  4. Place the fog lamps switch in the ON position.

Do the fog lamps illuminate?

Go to Step 3

Go to Fog Lamps Inoperative

3

Observe the fog lamp indicator of the instrument panel cluster (IPC).

Does the IPC fog lamp indicator illuminate?

Go to Step 4

Go to Step 5

4

Observe the fog lamp on indicator of the fog lamp switch.

Does the fog lamp on indicator of the fog lamp switch illuminate?

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

Go to Step 6

5

  1. Turn the ignition to the OFF position.
  2. Disconnect the IPC connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Turn the fog lamp switch to the ON position.
  5. Probe the fog lamps supply voltage circuit of the IPC with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 12

6

Using a test lamp connected to ground, backprobe the fog lamps supply voltage circuit of the fog lamp switch connector.

Does the test lamp illuminate?

Go to Step 7

Go to Step 10

7

  1. Disconnect the fog lamp switch connector.
  2. Using a test lamp connected to battery positive voltage, probe the ground circuit of the fog lamp switch connector.

Does the test lamp illuminate?

Go to Step 9

Go to Step 11

8

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

9

Inspect for poor connections at the harness connector of the fog lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

10

Repair the open or a high resistance in the fog lamp supply voltage circuit of the fog lamp switch. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

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11

Repair an open or a high resistance in the ground circuit of the fog lamp switch. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

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12

Repair the open or a high resistance in the fog lamp supply voltage circuit of the IPC. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

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13

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

Did you complete the replacement and the set up procedure?

Go to Step 15

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14

Replace the fog lamp switch. Refer to Instrument Panel Multifunction Switch Assembly Replacement in Instrument Panel, Gages, and Console.

Did you complete the replacement?

Go to Step 15

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15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2