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 9

4

  1. Place the gear selector in the PARK position.
  2. Select from the special functions, the Reverse Lamp Relay from the Rear Integration Module (RIM) output controls.
  3. With a scan tool, command the REVERSE relay ON and OFF.

Do you hear a click when you command the REVERSE relay ON and OFF?

Go to Step 7

Go to Step 5

5

  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 coil and a good ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 16

6

  1. Connect a test lamp between the control circuit of the REVERSE relay and the battery positive voltage circuit of the REVERSE relay coil.
  2. With a scan tool, command the REVERSE relay ON.

Does the test lamp illuminate?

Go to Step 13

Go to Step 12

7

  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 8

Go to Step 17

8

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 13

Go to Step 11

9

  1. Disconnect the harness connector of the inoperative backup lamp.
  2. 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 10

Go to Step 18

10

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 15

Go to Step 19

11

Test for an open or 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 23

Go to Step 19

12

Test the control circuit of the REVERSE relay for an open or short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 14

13

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 23

Go to Step 20

14

Inspect for poor connections at the harness connector of the RIM. 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 23

Go to Step 21

15

Inspect for poor connections at the backup lamps. 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 23

Go to Step 22

16

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

Did you complete the repair?

Go to Step 23

--

17

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 23

--

18

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

Did you complete the repair?

Go to Step 23

--

19

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 23

--

20

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

Did you complete the replacement?

Go to Step 23

--

21

Replace the RIM. Refer to Rear Integration Body Control Module Replacement in Body Control Systems.

Did you complete the replacement?

Go to Step 23

--

22

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

Did you complete the replacement?

Go to Step 23

--

23

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2