GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Lighting Systems?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition to the on position.
  2. Shift the gear selector to the REVERSE position.

Do both backup lamps illuminate?

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

Go to Step 3

3

Is only one lamp inoperative?

Go to Step 4

Go to Step 5

4

  1. Inspect the power supply or ground circuit for a poor connection or an open in the inoperative lamp. Refer to Circuit Testing in Wiring Systems.
  2. Repair the poor connection or open in the inoperative lamp. Refer to Wiring Repairs in Wiring Systems.
  3. If no fault is found, replace the inoperative lamp.

Did you complete the repair?

System OK

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5

Check the 10A TRN B/U fuse for an open.

Is the fuse open?

Go to Step 6

Go to Step 7

6

Repair a short to ground in the BackUp Lamp Feed Circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

System OK

--

7

  1. Connect a test lamp between ground and the ignition supply circuit at the park/neutral switch (backup lamp switch).
  2. Turn the ignition switch to the on position.

Does the test lamp illuminate?

Go to Step 8

Go to Step 11

8

  1. Connect a fused jumper between the ignition supply circuit and the backup lamp feed circuit of the park/neutral position switch or backup lamp switch.
  2. Turn the ignition switch to the on position.

Do the backup lamps illuminate?

Go to Step 10

Go to Step 9

9

Repair the open in Backup Lamp Feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

10

  1. Verify the adjustment of the back-up lamps switch or the park/neutral position switch.
  2. If the switch adjustment is acceptable, replace the switch. Refer to Backup Lamp Switch Replacement .

Is the repair complete?

System OK

--

11

Repair the open in the Ignition Feed Circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

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