GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Backup Lamps Inoperative

Step

Action

Value(s)

Yes

No

1
  1. Turn the ignition OFF.
  2. Remove and inspect the VEH B/U fuse.

Is the fuse open?

--

Go to Step 2

Go to Step 5

2

Using the J 35616 adapter, connect a self-powered test lamp from cavity B of the fuse to ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3
  1. Locate and repair CKT 1324 (LT GRN) for a short to ground.
  2. Replace the fuse.

Is the repair complete?

--

System OK

--

4
  1. Locate and repair CKT 1324 (LT GRN) for a intermittent short to ground.
  2. Replace the fuse.

Is the repair complete?

--

System OK

--

5
  1. Reinstall the VEH B/U fuse.
  2. Turn the headlamp switch to the PARK position .
  3. Turn the hazard flasher ON.
  4. Inspect the operation of the front and the rear lamps.

Are the front lamps operating and the rear are not?

--

Go to Step 6

Go to Step 7

6

Locate and repair CKT 1750 (BLK) for an open to ground between the rear lamps bussing block (RLBB) and G401.

Is the repair complete?

--

System OK

--

7
  1. Set the park brake.
  2. Turn the ignition ON.
  3. Turn the engine OFF.
  4. Place the transmission in REVERSE.
  5. Connect a test lamp from the fuse to ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

8

Locate and repair CKT 1324 (LT GRN) for an open between the underhood bussed electrical center (UBEC) and the RLBB.

Is the repair complete?

--

System OK

--

9

Remove and inspect B/U LP fuse.

Is the fuse open?

--

Go to Step 10

Go to Step 11

10
  1. Locate and repair CKT 839 (PNK) or CKT 24 (LT GRN) for a short to ground.
  2. Replace the fuse.

Is the repair complete?

--

System OK

--

11
  1. Reinstall the fuse.
  2. Disconnect the back-up lamp switch.
  3. Connect a test lamp from terminal A, manual, terminal C, automatic, to ground.

Does the test lamp light?

--

Go to Step 13

Go to Step 12

12

Locate and repair the open CKT 839 (PNK) between UBEC and the switch.

Is the repair complete?

--

System OK

--

13

Using J 35616 adaptor, connect a fused jumper wire from terminal A to terminal B for manual, terminal C to terminal F for automatic.

Do the back-up lamps light?

--

Go to Step 14

Go to Step 15

14

Replace the back-up lamp switch. Refer to the appropriate procedure in Transmission/Transaxle from the following list:

    •  Park/Neutral Position Switch Replacement . in Automatic Transmission - 4L60-E
    •  Park/Neutral Position Switch Replacement in Automatic Transmission 4L80-E
    •  Backup Lamp Switch Replacement Manual Transmission - NV3500
    •  Backup Lamp Switch Replacement in Manual Transmission NV4500

Is the repair complete?

--

System OK

--

15

Locate and repair the open in CKT 24 (LT GRN) between the switch and the UBEC.

Is the repair complete?

--

System OK

--