GM Service Manual Online
For 1990-2009 cars only

Backup Lamps Inoperative Domestic

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Apply the park brake.
  2. Turn ON the ignition, with the engine OFF.
  3. Place the gear shift selector lever in 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

Are both backup lamps inoperative?

Go to Step 4

Go to Step 6

4

  1. Disconnect the transmission range switch harness connector.
  2. Probe the battery positive voltage circuit of the transmission range switch with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 13

5

Install a fused jumper between the battery positive voltage circuit and the backup lamps supply voltage circuit of the transmission range switch connector. Refer to Circuit Testing in Wiring Systems.

Did the backup lamps illuminate?

Go to Step 10

Go to Step 12

6

  1. Remove the inoperative backup lamp bulb.
  2. Using a test lamp, probe between the supply voltage circuit and the ground circuit of the inoperative backup lamp .

Does the test lamp illuminate?

Go to Step 9

Go to Step 7

7

  1. Disconnect the tail lamp connector of the inoperative backup lamp.
  2. Probe the backup lamp supply voltage circuit of the tail lamp connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 15

8

Probe the backup lamp ground circuit of the tail lamp connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 11

Go to Step 14

9

Inspect for poor connections at the bulb socket 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 19

Go to Step 17

10

Inspect for poor connections at the harness connector of the transmission range switch. 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 19

Go to Step 16

11

Inspect for poor connections at the harness connector of the taillamp . 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 19

Go to Step 18

12

Repair the open or high resistance in the backup lamps supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 19

--

13

Repair the open or high resistance in the battery positive voltage circuit of the transmission range switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

--

14

Repair the open or high resistance in the ground circuit of the inoperative backup lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 19

--

15

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

Did you complete the repair?

Go to Step 19

--

16

Inspect the transmission range switch, adjust and/or replace if needed. Refer to Park/Neutral Position Switch Adjustment in Automatic Transaxle.

Did you complete the repair?

Go to Step 19

--

17

Replace the inoperative backup lamp bulb.

Did you complete the repair?

Go to Step 19

--

18

Replace the inoperative tail lamp assembly. Refer to Tail Lamp Replacement .

Did you complete the repair?

Go to Step 19

--

19

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Backup Lamps Inoperative Export

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Apply the park brake.
  2. Turn ON the ignition, with the engine OFF.
  3. Place the gear shift selector lever in 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

Are both backup lamps inoperative?

Go to Step 4

Go to Step 6

4

  1. Disconnect the transmission range switch harness connector.
  2. Probe the battery positive voltage supply circuit of the transmission range switch with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 16

5

Install a fused jumper across the battery positive voltage supply circuit and the backup lamps supply voltage circuit of the transmission range switch connector. Refer to Circuit Testing in Wiring Systems.

Did the backup lamps illuminate?

Go to Step 14

Go to Step 9

6

  1. Remove the inoperative backup lamp bulb.
  2. Using a test lamp, probe between the supply voltage circuit and the ground circuit of the inoperative backup lamp bulb socket.

Does the test lamp illuminate?

Go to Step 13

Go to Step 7

7

  1. Disconnect the tail lamp connector of the inoperative backup lamp.
  2. Probe the backup lamp supply voltage circuit of the tail lamp connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 17

8

Probe the backup lamp ground circuit of the tail lamp connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 15

Go to Step 18

9

  1. Disconnect the backup lamp relay connector.
  2. Probe the control circuit of the backup lamp relay connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 19

10

Probe the switch side feed circuit of the backup lamp relay connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 20

11

Probe the coil side ground circuit of the backup lamp relay connector with a test lamp that is connected to battery voltage.

Does the test lamp illuminate?

Go to Step 12

Go to Step 22

12

Install a fused jumper across the ignition positive voltage supply circuit and the backup lamps voltage supply circuit of the backup lamp relay connector. Refer to Circuit Testing in Wiring Systems.

Did the backup lamps illuminate?

Go to Step 24

Go to Step 21

13

Inspect for poor connections at the bulb socket 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 27

Go to Step 25

14

Inspect for poor connections at the harness connector of the transmission range switch. 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 27

Go to Step 23

15

Inspect for poor connections at the harness connector of the taillamp . 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 27

Go to Step 26

16

Repair an open or high resistance in the battery positive voltage supply circuit of the transmission range switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

17

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

Did you complete the repair?

Go to Step 27

--

18

Repair the an open or high resistance in the ground circuit of the inoperative backup lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

19

Repair the open or high resistance in the control circuit of the backup relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

20

Repair the open or high resistance in the switch side feed circuit of the backup relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

21

Repair the open or high resistance in the supply voltage circuit of the backup lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

22

Repair the open or high resistance in the coil side ground circuit of the backup relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 27

--

23

Inspect the transmission range switch, adjust and/or replace if needed. Refer to Park/Neutral Position Switch Adjustment in Automatic Transaxle.

Did you complete the repair?

Go to Step 27

--

24

Replace the backup lamp relay.

Did you complete the repair?

Go to Step 27

--

25

Replace the inoperative backup lamp bulb.

Did you complete the repair?

Go to Step 27

--

26

Replace the inoperative tail lamp assembly. Refer to Tail Lamp Replacement .

Did you complete the repair?

Go to Step 27

--

27

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2