GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Spark 🢒 Body Systems 🢒 Lighting 🢒 Fog Lamps Inoperative

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

Check fuse Ef9.

Is fuse Ef9 blown?

--

Go to Step 2

Go to Step 3

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

Is the repair complete?

--

System OK

--

3

Use a voltmeter to check fuse Ef9.

Does the battery voltage available at fuse Ef9 equal the specified value?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit from the battery to fuse Ef9.

Is the repair complete?

--

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.

Is the repair complete?

--

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, check the fog lamp relay socket at the connector for fog lamp relay terminal 30.

Does the voltage available at the fog lamp relay socket equal the specified value?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuse Ef9 and the fog lamp relay.

Is the repair complete?

--

System OK

--

9

At the fog lamp relay socket, use an ohmmeter to verify that the connector for relay terminal 86 is connected to ground.

Does the resistance equal the specified value?

0 ohms

Go to Step 11

Go to Step 10

10

Repair the ground circuit for the fog lamp relay.

Is the repair complete?

--

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 1 of the fog lamp connector.

Does the battery voltage available at terminal 1 of the fog lamp connector equal the specified value?

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.

Is the repair complete?

--

System OK

--

13

Use an ohmmeter (or test lamp) to check the ground at terminal 2 of the fog lamp connector.

Does the resistance equal the specified value?

0 ohms

Go to Step 15

Go to Step 14

14

Repair the fog lamp ground circuit.

Is the repair complete?

--

System OK

--

15

Replace the faulty fog lamp bulbs.

Is the repair complete?

--

System OK

--