GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2007 🢒 H3 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Backup Lamps Inoperative

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views , Automatic Transmission Related Connector End Views , or Manual Transmission Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn ON the ignition, with the engine OFF.
  2. Block the rear wheels.
  3. Place the gear selector or shifter in 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 4

Go to Step 5

4

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

Does the test lamp illuminate?

Go to Step 9

Go to Step 8

5
  1. Turn OFF the ignition.
  2. Connect a 15-amp fused jumper wire at the connector between the ignition positive voltage circuit and the backup lamp supply voltage circuit of the park/neutral position (PNP) switch, if equipped with an automatic transmission, or the backup lamp switch, if equipped with a manual transmission.
  3. Turn ON the ignition, with the engine OFF.

Do the backup lamps illuminate?

Go to Step 6

Go to Step 7

6

Inspect for poor connections at the harness connector of the PNP switch or backup lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

7

Repair one of the following conditions. Refer to Circuit Testing and Wiring Repairs .

    • The open, high resistance, or short to ground in the ignition positive voltage circuit or the backup lamps supply voltage circuit
    • The open or high resistance in the ground circuit

Did you complete the repair?

Go to Step 11

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8

Repair the open or high resistance in the backup lamp supply voltage circuit or the ground circuit.

Did you complete the repair?

Go to Step 11

--

9

Replace the inoperative bulb. Refer to Backup Lamp Bulb Replacement .

Did you complete the replacement?

Go to Step 11

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10

Adjust or replace the PNP switch if equipped with an automatic transmission, or the backup lamp switch if equipped with a manual transmission. Refer to Park/Neutral Position and Backup Lamp Switch Adjustment and Park/Neutral Position and Backup Lamp Switch Replacement or Backup Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3