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 OFF position.
  2. Turn the ignition switch to the RUN position.
    • The defogger ON indicator is off.
    • The defoggers are off.

Defoggers and Heated Mirrors Always On

2

  1. Press and release the defogger switch one time.
  2. Wait approximately 11 minutes.
    • The defogger ON indicator turns on.
    • The defoggers turns on.
    • The defogger ON indicator and the defoggers turn off after approximately 10 minutes.

3

  1. Press and release the defogger switch one time.
  2. Wait approximately 6 minutes.
    • The defogger ON indicator turns on.
    • The defoggers turn on.
    • The defogger ON indicator and the defoggers turn off after approximately 5 minutes.

Rear Window Defogger Inoperative

4

  1. Press and release the defogger switch one time.
  2. Wait approximately 15 seconds.
  3. Press and release the defogger switch a second time. Complete this action before time-out occurs.
  1. The defogger ON indicator turns on.
  2. The defoggers turn on.
  3. Pressing the switch for the second time causes the defogger ON indicator and the defoggers to turn off immediately.

Defoggers and Heated Mirrors Always On

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