GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Century (China) (CNG) 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Defogger System Check

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.

Refer to 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.
    • Refer to Defogger Indicator Inoperative

3
  1. Press and release the defogger switch one time.
  2. Wait approximately 6 minutes.
    • The defogger ON indicator comes on.
    • The defoggers come on.
    • The defogger ON indicator and the defoggers turn off after approximately 5 minutes.

Refer to Defoggers and Heated Mirrors 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 comes on.
  2. The defoggers come on.
  3. Pressing the switch for the second time causes the defogger ON indicator and the defoggers to turn off immediately.

Refer to Defoggers and Heated Mirrors Always On

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