GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn the ignition to the ON position.
  2. Place the gear selector lever to the REVERSE position.

Do both backup lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Is only one lamp inoperative?

Go to Step 9

Go to Step 4

4

  1. Disconnect the back up lamp relay.
  2. Probe the switch side battery positive voltage circuit of the back up lamp relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

Connect a 10-amp fused jumper between the switch side battery positive voltage circuit of the backup lamp relay and the back up lamp voltage supply circuit of the backup lamp relay.

Do the back up lamps illuminate?

Go to Step 8

Go to Step 6

6

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

Did you find and correct the condition?

Go to Step 12

Go to Step 7

7

Inspect for poor connections at the fuse block - rear. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

8

Inspect for poor connections at the backup lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

9

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

Did you complete the repair?

Go to Step 12

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10

Replace the fuse block - rear. Refer to Power and Grounding Component Views .

Did you complete the replacement?

Go to Step 12

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11

Replace the backup lamp relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2