GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn the ignition switch to the ON position. Do not start the engine.
  2. Automatic transmissions: Depress the brake pedal and move the shift lever to the REVERSE position.
  3. Manual transmissions: Depress the clutch pedal and place the shifter into the REVERSE position.

Both of the backup lamps illuminate.

2

Automatic transmissions: Depress the brake pedal and move the shift lever to the PARK position.

Manual transmissions: Depress the clutch pedal and place the shifter into the NEUTRAL position.

Both of the backup lamps turn OFF.

Backup Lamps Always On

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.