GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn ON the ignition, with the engine OFF.
  2. Press and hold the brake pedal.
  3. Place the gear selector in the REVERSE position.

Do the backup lamps illuminate?

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

Go to Step 3

3

Are both backup lamps inoperative?

Go to Step 4

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Remove the REVERSE relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the battery positive voltage circuit of the REVERSE relay switch and a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 11

5

Connect a 10 amp fused jumper between the battery positive voltage circuit of the REVERSE relay switch and the supply voltage circuit of the backup lamps.

Do the backup lamps illuminate?

Go to Step 9

Go to Step 8

6

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inoperative backup lamp.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the supply voltage circuit of the inoperative backup lamp and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 13

7

Connect a test lamp between the supply voltage circuit of the inoperative backup lamp and the ground circuit of the inoperative backup lamp.

Does the test lamp illuminate?

Go to Step 10

Go to Step 12

8

Test for an open or a high resistance in the supply voltage circuit of the backup lamps. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

9

Inspect for poor connections at the REVERSE relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 14

10

Inspect for poor connections at the harness connector of the inoperative backup lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

11

Repair an open or high resistance in the battery positive voltage circuit of the REVERSE relay switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

12

Repair an open or a high resistance in the ground circuit of the backup lamps. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

13

Repair an open or a high resistance in the supply voltage circuit of the inoperative backup lamp. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

14

Replace the REVERSE relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 16

--

15

Replace the inoperative backup lamp. Refer to Backup Lamp Replacement .

Did you complete the replacement?

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2