GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.

1

Exchange the fog lamp relay with known good relay.

Do fog lamps operate?

--

Go to Step 2

Go to Step 3

2

Replace fog lamp relay.

Is repair complete?

--

Go to Exterior Lights System Check

--

3

Exchange the fog lamp cutoff relay with a known good relay.

Do the fog lamps operate?

--

Go to Step 4

Go to Step 5

4

Replace the fog lamp cutoff relay.

Is the repair complete?

--

Go to Exterior Lights System Check

--

5

  1. Place the turn/hazard headlamp switch in the PARK position.
  2. Backprobe the fog lamp switch with a test lamp between terminal B and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 7

6

  1. Turn the fog lamp switch to the ON position.
  2. Backprobe the fog lamp switch with the test lamp between terminal A and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

7

Repair the open in circuit 32 between splice S232 and the fog lamp switch. Refer to Wiring Repairs in Wiring Systems

Is the repair complete?

--

Go to Exterior Lights System Check

--

8

  1. Disconnect the fog lamp relay.
  2. Connect the test lamp between terminal 86 of the fog lamp harness connector and ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

9

Replace the fog lamp switch.

Is repair complete?

--

Go to Exterior Lights System Check

--

10

  1. Disconnect the fog lamp cutoff relay.
  2. Connect the test lamp between terminal 86 of the fog lamp cutoff relay harness connector and ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 13

11

Repair the open in circuit 317 between the fog lamp switch and the fog lamp relay. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Exterior Lights System Check

--

12

  1. Reconnect the fog lamp relay.
  2. Connect the fused jumper between terminal 87A of the fog lamp cutoff harness connector and ground.

Do the fog lamps operate?

--

Go to Step 14

Go to Step 15

13

Repair the open in circuit 940 between splice S151 and the fog lamp cutoff relay. Refer to Wiring Repairs in Wiring systems.

--

Go to Exterior Lights System Check

--

14

Repair open in circuit 150 between the fog lamp cutoff relay and ground G102. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Exterior Lights System Check

--

15

  1. Reconnect the fog lamp cutoff relay.
  2. Disconnect the fog lamp relay.
  3. Connect the test lamp between terminal 30 and terminal 86 of the fog lamp relay harness connector.

Does the test lamp light?

--

Go to Step 16

Go to Step 17

16

Connect the test lamp between terminal 85 and terminal 86 of the fog lamp relay harness connector and ground.

Does the test lamp light?

--

Go to Step 18

Go to Step 19

17

Repair the open in circuit 1317 between the fog lamp cutoff relay and the fog lamp relay.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Exterior Lights System Check

--

18

Repair the open in circuit 34 between the fog lamp relay and splice S122. Refer to Wiring Repairs In Wiring Systems.

Is the repair complete?

--

Go to Exterior Lights System Check

--

19

Repair the open in circuit 150 between the fog lamp relay and splice S115. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Exterior Lights System Check

--