GM Service Manual Online
For 1990-2009 cars only

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Action

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Schematic Reference: Fog Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the low beam headlamps.
  3. Observe the front fog lamps.
  4. Turn ON and OFF the front fog lamps.
  5. Turn OFF the ignition .

Did the front fog lamps operate properly?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Position the front fog lamp switch to the OFF position.
  4. With a scan tool, observe the Front Fog Lamp Switch parameter in the dash integration module (DIM) Inputs data list.

Does the scan tool indicate that the front fog lamp switch parameter is Idle?

Go to Step 4

Go to Step 7

4

With a scan tool, observe the Front Fog Lamp Relay status in the DIM Outputs data list.

Does the scan tool indicate the fog lamp relay parameter is Off?

Go to Step 5

Go to Step 11

5

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

Did the fog lamps turn OFF?

Go to Step 6

Go to Step 14

6

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

Does the test lamp illuminate?

Go to Step 8

Go to Step 13

7

  1. Turn OFF the ignition.
  2. Disconnect the multifunction, turn signal switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool observe the Front Fog Lamp Switch parameter.

Does the scan tool indicate the Front Fog Lamp Switch parameter is Idle?

Go to Step 10

Go to Step 9

8

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

Did you find and correct the condition?

Go to Step 18

Go to Step 11

9

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

Did you find and correct the condition?

Go to Step 18

Go to Step 11

10

Test the front fog lamp switch signal circuit for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

11

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

Did you find and correct the condition?

Go to Step 18

Go to Step 15

12

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

Did you find and correct the condition?

Go to Step 18

Go to Step 16

13

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

Did you find and correct the condition?

Go to Step 18

Go to Step 17

14

Repair the short to voltage in the front fog lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did to complete the repair?

Go to Step 18

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15

Important:: Perform the setup procedure for the DIM.

Replace the DIM. Refer to Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 18

--

16

Replace the multifunction, turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 18

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17

Replace the fog lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 18

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18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2