GM Service Manual Online
For 1990-2009 cars only

Front Fog Lamps Inoperative 1.6L and 1.8L

Diagnostic Aids

The front fog lamps will not operate unless the illumination lamps or daytime running lamps are ON. If the illumination lamps or daytime running lamps are not operating, repair that problem before attempting to diagnose the fog lamps.

Step

Action

Values

Yes

No

1

Inspect fuse Ef24.

Is fuse Ef24 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace the fuse.

Did you complete the action?

--

System OK

--

3

Use a voltmeter to inspect fuse Ef24.

Does the battery voltage available at fuse Ef24 measure within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit from the battery to fuse Ef24.

Did you complete the repair?

--

System OK

--

5

Remove the fog lamp relay and temporarily substitute a known good relay, such as the headlamp relay. Do not substitute the illumination lamp relay.

Do the fog lamps work with the substituted relay?

--

Go to Step 6

Go to Step 7

6

  1. Return the substituted relay to its original position.
  2. Replace the inoperative fog lamp relay.

Did you complete the replacement?

--

System OK

--

7

  1. Return the substituted relay to its original position, but do not reinstall the fog lamp relay.
  2. Turn ON the exterior lamps and the front fog lamps.
  3. Using a voltmeter, inspect the fog lamp relay socket at the connector for fog lamp relay terminal 30.

Does the voltage available at the fog lamp relay socket measure within the specified range?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuse Ef24 and the fog lamp relay.

Did you complete the repair?

--

System OK

--

9

At the fog lamp relay socket, use an ohmmeter to verify that the connector for relay terminal 85 is connected to ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 11

Go to Step 10

10

Repair the ground circuit for the fog lamp relay.

Did you complete the repair?

--

System OK

--

11

  1. Reinstall the fog lamp relay.
  2. Turn ON the exterior lamps and the front fog lamps.
  3. Test for voltage at terminal 2 of the fog lamp connector.

Does the battery voltage available at terminal 2 of the fog lamp connector measure within the specified range?

11-14 V

Go to Step 13

Go to Step 12

12

Repair the open circuit between the fog lamp relay terminal 87 and the fog lamps.

Did you complete the repair?

--

System OK

--

13

Use an ohmmeter, or test lamp, to check the ground at terminal 1 of the fog lamp connector.

Is the resistance equal to the specified value?

0 ohms

Go to Step 15

Go to Step 14

14

Repair the fog lamp ground circuit.

Did you complete the repair?

--

System OK

--

15

Replace the faulty fog lamp bulbs.

Did you complete the replacement?

--

System OK

--

Front Fog Lamps Inoperative 2.0L

Diagnostic Aids

The front fog lamps will not operate unless the illumination lamps or daytime running lamps are ON. If the illumination lamps or daytime running lamps are not operating, repair that problem before attempting to diagnose the fog lamps.

Step

Action

Values

Yes

No

1

Inspect fuse Ef24, Ef28.

Is fuse Ef24, Ef28 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace the fuse.

Did you complete the action?

--

System OK

--

3

Use a voltmeter to inspect fuse Ef24, Ef28.

Does the battery voltage available at fuse Ef24, Ef28 measure within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit from the battery to fuse Ef24 and Ef28.

Did you complete the repair?

--

System OK

--

5

Remove the fog lamp relay daytime running lamp (DRL) relay and temporarily substitute a known good relay, such as the headlamp relay. Do not replace DRL relay on other relay. Do not substitute the illumination lamp relay.

Do the fog lamps work with the substituted relay?

--

Go to Step 6

Go to Step 7

6

  1. Return the substituted relay to its original position.
  2. Replace the inoperative fog lamp relay.

Did you complete the replacement?

--

System OK

--

7

  1. Return the substituted relay to its original position, but do not reinstall the fog lamp relay.
  2. Turn ON the exterior lamps and the front fog lamps.
  3. Using a voltmeter, inspect the fog lamp relay socket at the connector for fog lamp relay terminal 30 and DRL relay socket at the connector for DRL relay terminal 30.

Does the voltage available at the fog lamp relay socket and DRL relay socket measure within the specified range?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuse Ef24 and the fog lamp relay, fuse Ef28 and DRL relay.

Did you complete the repair?

--

System OK

--

9

At the fog lamp relay socket, use an ohmmeter to verify that the connector for relay terminal 87 is connected to ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 11

Go to Step 10

10

Repair the ground circuit for the DRL relay.

Did you complete the repair?

--

System OK

--

11

  1. Reinstall the fog lamp relay.
  2. Turn ON the exterior lamps and the front fog lamps.
  3. Test for voltage at terminal 2 of the fog lamp connector.

Does the battery voltage available at terminal 2 of the fog lamp connector measure within the specified range?

11-14 V

Go to Step 13

Go to Step 12

12

Repair the open circuit between the fog lamp relay terminal 87 and the fog lamps.

Did you complete the repair?

--

System OK

--

13

Use an ohmmeter, or test lamp, to check the ground at terminal 1 of the fog lamp connector.

Is the resistance equal to the specified value?

0 ohms

Go to Step 15

Go to Step 14

14

Repair the fog lamp ground circuit.

Did you complete the repair?

--

System OK

--

15

Replace the faulty fog lamp bulbs.

Did you complete the repair?

--

System OK

--