GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Rear Fog Lamps Inoperative

Rear Fog Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Were you sent from Foglamp System Check.

--

Go to Step 2

Go to Fog Lights System Check

2

Perform the BCM Diagnostic System Check?

Refer to Diagnostic System Check - Body Control System .

Are any DTCs stored in memory related to foglamp operation?

--

Go to applicable diagnostic table

Go to Step 3

3
  1. Using a scan tool select BCM data display.
  2. Monitor the rear fog lamp switch status while operating the switch on and off.

Does the scan tool display the switch status as ACTIVE and INACTIVE?

--

Go to Step 12

Go to Step 4

4

Check the F/TNK DR MiniFuse® #32.

Is the fuse open?

--

Go to Power Distribution

Go to Step 5

5
  1. Disconnect the BCM connector C2.
  2. Using a test light probe terminal D5 (circuit 187).

--

Go to Step 9

Go to Step 6

6
  1. Disconnect the rear fog lamp switch connector.
  2. Using a DMM measure the resistance of circuit 187 from the switch connector terminal 6, to the BCM connector C2 terminal D5.

Is the resistance within specified values?

0-2 ohms

Go to Step 7

Go to Step 10

7
  1. Remove the F/TNK DR MiniFuse® #32.
  2. Using a DMM measure the resistance of circuit 2840 from the fuse terminal in the instrument panel electrical center, to the rear fog lamp switch connector terminal 1.

Is the resistance within specified values?

0-2 ohms

Go to Step 8

Go to Step 11

8

Replace the rear fog lamp switch.

Refer to Fog Lamp Switch Replacement .

Is the repair complete?

--

Go to Fog Lights System Check

--

9

Replace the BCM.

Refer to Body Control Module Replacement Body Control Module (BCM) Programming/RPO Configuration .

Is the repair complete?

--

Go to Fog Lights System Check

--

10

Repair the open in circuit 187.

Is the repair complete?

--

Go to Fog Lights System Check

--

11

Repair the open in circuit 2840.

Is the repair complete?

--

Go to Fog Lights System Check

--

12

With the scan tool indicating the rear fog lamp switch as ACTIVE, is the rear fog lamp indicator illuminated?

--

Go to Step 19

Go to Step 13

13

Check the RR FOG LP MiniFuse® #1.

Is the fuse open?

--

Go to Step 18

Go to Step 14

14
  1. Disconnect the BCM connector C1.
  2. Connect a fused jumper wire from the BCM connector C1 terminal B3 to ground.

Do the rear fog lamps illuminate?

--

Go to Step 9

Go to Step 15

15
  1. Remove the RR FOG LP Micro Relay #37.
  2. Using a DMM measure the resistance of circuit 1901, from the relay terminal in the underhood electrical center to the BCM connector C1 terminal B3.

Is the resistance within specified values?

0-2 ohms

Go to Step 16

Go to Step 17

16

Replace the RR FOG LP Micro Relay #37.

Is the repair complete?

--

Go to Fog Lights System Check

--

17

Repair the open in circuit 1901.

Is the repair complete?

--

Go to Fog Lights System Check

--

18

Repair the short to ground in circuit 122.

Is the repair complete?

--

Go to Fog Lights System Check

--

19
  1. Disconnect a rear fog lamp bulb connector.
  2. Connect a test light between the connector terminals A and G.

With the scan tool indicating switch status as ACTIVE, does the test light illuminate?

--

Go to Step 21

Go to Step 20

20

Connect a test light from the rear fog lamp bulb connector terminal A to ground.

With the scan tool indicating switch status as ACTIVE, does the test light illuminate?

--

Go to Step 22

Go to Step 23

21

Replace the rear fog lamp bulbs.

Refer to Rear Fog Lamp Bulb Replacement .

Is the repair complete?

--

Go to Fog Lights System Check

--

22

Repair the open ground circuit 150.

Is the repair complete?

--

Go to Fog Lights System Check

--

23

Repair the open in circuit 34.

Is the repair complete?

--

Go to Fog Lights System Check

--