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:

• | Heater and A/C programmer

• | Instrument cluster

• | Passenger temperature control

• | 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 lights light at the current dimming level:

• | Astray lamp

• | Door handle flood lamps (Buick)

• | Door switch flood lamps (Buick)

• | Fog lamp switch (Oldsmobile)

• | Headlamp switch (Buick)

• | Heater and A/C control

• | Instrument cluster

• | Panel dimming switch (Oldsmobile)

• | Passenger temperature control

• | Power mirror switch (Oldsmobile)

• | Power window switches (Oldsmobile)

• | PRNDL lamps (Buick)

• | Radio

• | Release switch (Oldsmobile)

• | Seat switches (Oldsmobile)

• | Seat/lock switches (Oldsmobile)

• | Shift select switch lamp (Oldsmobile)

• | Steering wheel controls

• | Traction control switch (Oldsmobile)

• | 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.