GM Service Manual Online
For 1990-2009 cars only

Backup Lamp Inoperative - One Lamp Pickup

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that one of the backup lamps is inoperative.

Do the backup lamps operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Inspect the inoperative bulb for a open filament and the socket for damaged or corroded contacts

Was a problem found?

--

Go to Step 4

Go to Step 5

4

Replace the inoperative bulb or clean/replace the socket.

Is the repair complete?

--

Go to Step 9

--

5

  1. Connect a J 39200 Digital Multimeter DMM) between CKT 1324 (LT GRN) at the inoperative lamp socket and ground. Refer to Circuit Testing in Wiring Systems.
  2. Engine off, turn the ignition switch to the RUN position.
  3. Set the parking brake and block the wheels.
  4. Place the transmission in the REVERSE position.

Is voltage present?

B+

Go to Step 7

Go to Step 6

6

Locate and repair the open or high resistance in CKT 1324 (LT GRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

7

Connect the J 39200 DMM at the inoperative lamp socket between CKT 1750/2250 (BLK) and ground to check for continuity. Refer to Circuit Testing in Wiring Systems.

Is there continuity?

--

Go to Step 4

Go to Step 8

8

Locate and repair the open in CKT 1750/2250 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Backup Lamp Inoperative - One Lamp Utility

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that one of the backup lamps is inoperative.

Do the backup lamps operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Inspect the inoperative bulb for a open filament and the socket for damaged or corroded contacts

Was a problem found?

--

Go to Step 4

Go to Step 5

4

Replace the inoperative bulb or clean/replace the socket.

Is the repair complete?

--

Go to Step 9

--

5

  1. Connect a J 39200 Digital Multimeter (DMM) between CKT 1324 (LT GRN) at the inoperative lamp socket and ground. Refer to Circuit Testing in Wiring Systems.
  2. Engine off, turn the ignition switch to the RUN position.
  3. Set the parking brake and block the wheels.
  4. Place the transmission in the REVERSE position.

Is voltage present?

B+

Go to Step 7

Go to Step 6

6

Locate and repair the open or high resistance in CKT 1324 (LT GRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

7

Connect the J 39200 DMM at the inoperative lamp socket between CKT 150 (BLK) and ground to check for continuity. Refer to Circuit Testing in Wiring Systems.

Is there continuity?

--

Go to Step 4

Go to Step 8

8

Locate and repair the open in CKT 150/1350 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3