GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuse F4.

Is fuse F4 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace fuse F4.

Is the repair complete?

--

System OK

--

3

Use a voltmeter to verify that battery voltage is available at fuse F4.

Does the voltage measure within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the power supply circuit for fuse F4.

Is the repair complete?

--

System OK

--

5

  1. Remove and examine the backup lamp bulbs.
  2. Test the bulbs by connecting them to the vehicle battery with jumper wires.

Are the bulbs defective?

--

Go to Step 6

Go to Step 7

6

Replace the defective bulbs.

Is the repair complete?

--

System OK

--

7

  1. Reinstall the backup lamps after testing.
  2. Turn the ignition ON.
  3. Disconnect the backup switch connector.
  4. Measure the voltage at terminal 1 of the backup switch, or terminal 7 of the park/neutral position switch if the vehicle has an automatic transaxle.

Does the voltage measure within the specified range?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuse F4 and the backup switch.

Is the repair complete?

--

System OK

--

9

  1. Turn the ignition ON.
  2. Apply the parking brake.
  3. Block the wheels to prevent the vehicle from moving.
  4. Put the transaxle in REVERSE.
  5. Use a voltmeter to measure voltage at terminal 2 of the backup switch, or terminal 8 of the park/neutral position switch if the vehicle has an automatic transaxle.

Does the voltage measure within the specified range?

11-14 V

Go to Step 11

Go to Step 10

10

Replace the backup switch.

Is the repair complete?

--

System OK

--

11

  1. Remove one of the backup lamps.
  2. Turn the ignition ON.
  3. Apply the parking brake.
  4. Block the wheels to prevent the vehicle from moving.
  5. Put the transaxle in REVERSE.
  6. Use a voltmeter to measure voltage at the positive terminal of the backup lamp socket.

Does voltage at the lamp socket measure within the specified range?

11-14 V

Go to Step 12

Go to Step 13

12

Repair the ground circuit of the backup lamps.

Is the repair complete?

--

System OK

--

13

Repair the open circuit between the backup lamps and the backup switch.

Is the repair complete?

--

System OK

--