GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Fog Lights System Check performed?

--

Go to Step 2

Go to Fog Lights System Check

2

  1. Connect a Scan Tool to the data link connector (DLC).
  2. Inspect the IPC input: rear fog lamps switch.

Does the rear fog lamps switch operate properly?

--

Go to Step 3

Go to Step 7

3

Remove the fog lamp relay from the rear compartment relay center 1.

Do the rear fog lamps turn off?

--

Go to Step 4

Go to Step 10

4

  1. Re-install the rear fog lamp relay.
  2. Disconnect the body control module (PZM) connector C2.

Are the rear fog lamps on?

--

Go to Step 5

Go to Step 6

5

Inspect CKT 1977 (YEL) for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Is CKT 1977 OK?

--

Go to Step 11

Go to Step 13

6

Replace the body control module (PZM). Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

Go to Fog Lights System Check

--

7

Disconnect the headlamp switch connector C1.

Do the rear fog lamps turn off?

--

Go to Step 8

Go to Step 9

8

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

--

Go to Fog Lights System Check

--

9

Inspect CKT 187 (LT BLU) for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Is CKT 187 OK?

--

Go to Step 12

Go to Step 13

10

Repair the short to voltage in CKT 122 (RED). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Fog Lights System Check

--

11

Replace the rear fog lamp relay.

Is the repair complete?

--

Go to Fog Lights System Check

--

12

Replace the instrument panel cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Fog Lights System Check

--

13

Repair the suspect wiring. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Fog Lights System Check

--