GM Service Manual Online
For 1990-2009 cars only

Exterior Lights Diagnostic System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn the headlamp switch to the PARK position.
  2. Turn the headlamp switch to the OFF position.
    • Park lamps, rear side marker, rear tail lamps, and license plate lamps are illuminated.
    • Lamps turn off.

2

  1. Parking brake applied, turn the ignition switch to the on position.
  2. Move the turn signal lever into the LH turn position.
  3. Move the turn signal lever into the RH turn position.
  4. Return the turn signal lever to the OFF position.
    • The LH turn signal lamps flash ON and OFF.
    • The RH turn signal lamps flash ON and OFF.
    • Turn signal lamps turn off.

3

  1. Move the hazard warning switch to the ON position.
  2. Move the hazard warning switch to the OFF position.
    • The front and rear turn signal lamps flash ON and OFF.
    • Lamps turn off.

Hazard Lamps Inoperative

4

  1. Depress the brake pedal.
  2. Release the brake pedal.
    • The center high mounted stop lamp (CHMSL) and rear stop lamps are illuminated.
    • The center high mounted stop lamp (CHMSL) and rear stop lamps turn OFF.
    •  Stop Lamps Inoperative
    •  Stop Lamps Inoperative

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