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

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Place the front fog lamp switch in the OFF position.
  4. With a scan tool, observe the Front Fog Lamp Relay Status in the instrument panel module (IPM) outputs data list.

Does the scan tool indicate the front fog lamp relay status parameter is OFF?

Go to Step 3

Go to Step 5

3

  1. Turn OFF the ignition.
  2. Disconnect the front fog lamp relay. Refer to Relay Replacement .
  3. Turn ON the ignition, with the engine OFF.

Do the front fog lamps turn OFF?

Go to Step 4

Go to Step 11

4

  1. Turn OFF the ignition .
  2. Connect a test lamp between the front fog lamp relay control side supply voltage circuit and the front fog lamp relay control circuit.
  3. Place the front fog lamp switch in the OFF position.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 6

Go to Step 10

5

  1. Turn OFF the ignition.
  2. Disconnect the C2 harness connector at the turn signal/multifunction switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Front Fog Lamp Relay Status parameter in the IPM outputs data list.

Does the scan tool indicate the front fog lamp relay status parameter is OFF?

Go to Step 9

Go to Step 7

6

Test the front fog lamp relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 8

7

Test the front fog lamp switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 8

8

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

Did you find and correct the condition?

Go to Step 15

Go to Step 12

9

Inspect for poor connections at the harness connector of the turn signal/multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 13

10

Inspect for poor connections at the front fog lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 14

11

Locate and repair a short to voltage in the front fog lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did to complete the repair?

Go to Step 15

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12

Replace the IPM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

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13

Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement .

Did you complete the replacement?

Go to Step 15

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14

Replace the front fog lamp relay. Refer to Relay Replacement .

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