For 1990-2009 cars

Step | Action | Normal Result(s) | Abnormal Result(s)*
--- | --- | --- | ---
1 | Turn the ignition switch to the RUN position. | The following VF displays light:

• | The heater and A/C programmer

• | The instrument cluster

• | The passenger temperature control

• | The radio

Vacuum Fluorescent Display Inoperative - Heater and Air Conditioning (A/C) Control

2 | Place the headlamp switch in the PARK position. | The above VF displays dim and the following interior lamps light at the current dimming level:

• | The ashtray lamp

• | The door handle flood lamps (Buick)

• | The door switch flood lamps (Buick)

• | The fog lamp switch (Oldsmobile)

• | The headlamp switch (Buick)

• | The heater and A/C control

• | The instrument cluster

• | The panel dimming switch (Oldsmobile)

• | The passenger temperature control

• | The power mirror switch (Oldsmobile)

• | The power window switches (Oldsmobile)

• | The PRNDL lamps (Buick)

• | The radio

• | The release switch (Oldsmobile)

• | The seat switches (Oldsmobile)

• | The seat/lock switches (Oldsmobile)

• | The shift select switch lamp (Oldsmobile)

• | The steering wheel controls

• | The traction control switch (Oldsmobile)

• | The trip odometer reset switch (Buick)

• | Vacuum Fluorescent Displays Do Not Change Intensity - All

• | Incandescent Lamps Inoperative

• | Incandescent Lamps Inoperative

3 | Operate the dimming switch in both directions, through the full range of the switch. | In one direction, the lamps become dim. In the other direction, the lamps become bright. |

• | Vacuum Fluorescent Displays Do Not Change Intensity - All

• | Incandescent Lamps Inoperative

• | Incandescent Lamps Inoperative

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