GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views or Automatic Transmission Related Connector End Views in Automatic Transmission - 4L60-E/4L65-E

1

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

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

Verify that the backup lamps are always ON.

Do the backup lamps operate normally?

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

Go to Step 3

3

  1. Block the wheels or set the parking brake.
  2. Turn the ignition switch to the RUN position. Do not start the engine.
  3. Disconnect the backup lamp switch manual transmission (M/T) or the park/neutral position switch automatic transmission (A/T).

Do the backup lamps remain illuminated?

Go to Step 4

Go to Step 5

4

Replace or adjust the park/neutral position and backup lamp switch. Refer to Park/Neutral Position Switch Replacement or Park/Neutral Position Switch Adjustment in Automatic Transmission - 4L60-E/4L65-E.

Did you complete the repair?

Go to Step 6

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5

Repair the short to power in the backup lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 6

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6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3