For 1990-2009 cars

### Exterior Lighting

#### Backup Lamps

The backup lamps turn on when the ignition is on and the shift lever is moved to the REVERSE position. The park/neutral position switch controls the backup lamps.

#### High Mounted Stoplamp

The high mounted stoplamp is in the center of the rear shelf panel. The high mounted stoplamp operates with the rear stoplamps. The high mounted stoplamp does not light during the turn or the hazard system operation.

#### Daytime Running Lamps

The Daytime Running Lamps (DRL) system operates when the vehicle shift lever is moved out of the PARK position. For circuit description and diagnosis, refer to Headlights/Daytime Running Lights (DRL) Circuit Description .

#### Fog Lamps - Eighty Eight/LSS/Pontiac

The fog lamps light when the park or the low beam headlamps are on and the fog lamp switch is set to the ON position.

#### Front Cornering Lamps

Cornering lamps are located toward the outside of the headlamp. The cornering lamp has a halogen bulb that lights with the turn signal to illuminate the peripheral area of the turn.

#### Front Park/Turn Signal Lamps

Buick and Oldsmobile park lamps are operated by pressing either the parklamp switch or the headlamp switch. Pontiac park lamps are operated by pulling out the headlamp switch one or two positions. On all models, the turn signal lamps are activated by the multi-function lever.

#### Front Side Marker Lamps

The side marker lamps turn on whenever the park lamps are on.

#### Hazard Flasher

When the hazard warning button is depressed, the hazard flasher is energized. The hazard flasher operates in all of the ignition switch positions. The turn signals do not work when the hazard flasher is in the ON position.

When the hazard flasher is operating, the turn signal indicator lamps, all front turn signal lamps, all rear turn signal lamps, and the front side marker lamps flash. All of the signal lamps will light continuously if the brake pedal is depressed while the hazard flasher is on.

#### Headlamps

Each headlamp consists of one halogen low beam bulb and one halogen high beam bulb. The bulbs are not interchangeable. The headlamps are assembled to the headlamp housing panel and can be adjusted by using the adjustment procedures in this section. The headlamps are controlled by the head/park lamp switch or the twilight sentinel system, if equipped.

#### License Plate Lamp

The license plate lamp is located in the license pocket. The lamp illuminates whenever the head/park lamps are on.

#### Rear Compartment Lamp

The rear compartment lamp operates whenever the rear compartment lid is raised.

#### Rear Sidemarker Lamps

The rear side marker lamps operate in conjunction with the taillamp circuit. The lamps are activated when the head/park lamps are on.

#### Taillamps

The taillamps activate when the head/park lamps are on. The stoplamp function increases the illumination of the taillamps when the brake pedal is depressed. The turn signal function is activated when the multi-function lever is moved up or down.

#### Turn Signal Operation

The turn signal lamps are combined with the parking lamps in the front and with the stop and taillamps in the rear. The turn signal lamps operate only when the ignition switch is in the RUN position. When the multi-function turn signal lever is in the Neutral position, stepping on the brake pedal illuminates the rear stoplamps on both sides and the high mounted stoplamp. When the lever operates either turn signal, stepping on the brake pedal turns ON the high mounted stoplamp and the stoplamp on the non-flashing side. The flasher that is used in the circuit controls only the turn signal.

The lane-change turn signal feature is standard equipment. The driver has the option of moving the multi-function turn signal lever to a detent stop when making a partial turn, such as when changing lanes. The signal lamps flash as long as the driver holds the lever in the detent stop position. The signal lamps cancel automatically when the driver releases the lever. Use the detent position in order to signal a shallow turn to change lanes. Move the multi-function turn signal lever past the detent position to the travel limit in either direction in order to provide the conventional turn signal operation.

#### Twilight Sentinel

The twilight sentinel is a feature that provides for the automatic ON-OFF control of the headlamps in response to the level of ambient light. It also keeps the lamps on for a preselected time period after the ignition is turned to the OFF position. The headlamps turn OFF automatically after the preselected time period elapses.

The system consists of the following components:

• | The light sensitive photocell sensor

• | The lamp control module

• | The time delay control with an ON/OFF switch

The automatic twilight sentinel circuit parallels the regular head/park lamp switch such that the head/park lamp switch must be OFF for automatic control.

The photocell sensor is mounted with the light sensitive surface face up, in the instrument panel trim panel. This positioning exposes the photocell to the skylight through the windshield. The lamp control module is mounted behind the center of the instrument panel, above the HVAC case.

The system turns the headlamps ON under the following conditions:

• | When the ignition switch is in the ON position

• | When the head/park lamp switch is turned OFF

• | When the twilight sentinel control is turned ON

• | Whenever road illumination becomes necessary

As daylight increases in the morning and illumination is no longer needed, the system turns the headlamps OFF.

A time delay circuit in the lamp control module reduces the probability of the headlamps switching ON or OFF while the vehicle passes under viaducts, trees, bright lights, etc. The time is normally 10-30 seconds and may not be adjusted. The variable twilight sentinel control adjusts only the time delay period during which the headlamps remain ON after the ignition is turned to the OFF position. This time delay may be adjusted from 3 seconds to 4 minutes.

Setting the twilight sentinel system control to the OFF position allows normal headlamp operation using the head/park lamp switch. If the head/park lamp switch is moved to the ON position , the headlamps remain ON after the ignition is turned to the OFF position, regardless of the setting on the twilight sentinel control. A warning chime sounds when the driver-side door opens. This chime is a reminder to turn the head/park lamp switch OFF.

#### Underhood Lamp - Buick

The underhood lamp lights when the following conditions exist:

• | The hood is raised.

• | The head/park lamp switch is in the ON position.

### Interior Lamps

#### Ashtray Lamps

The ashtray lamp is located on the top center of the ashtray. The ashtray lamp lights when the park lamps or the headlamps are turned ON.

#### Courtesy and Reading Lamps

The courtesy lamps and the reading lamps are located on the roof rail. Push in the switch to turn the lamps ON and OFF. The lamps also light when a door opens or when the interior lamps turn ON.

#### Lower IP Courtesy Lamps

The courtesy lamps are located beneath the outer ends of the sound insulators. The courtesy lamps light when either door opens or when the interior lamps turn ON.

#### Instrument Panel Compartment Lamp

The instrument panel compartment lamp lights whenever the door to the instrument panel compartment opens. The instrument panel compartment lamps turn OFF whenever the door to the instrument panel compartment closes.

#### Lighted Vanity Visor Mirror

The lighted visor mirrors are located in the center of each visor. The lamps turn ON and OFF by opening and closing the vanity mirror cover.

### Head/Park Lamp Switch

The head/park lamp switch is located in the instrument panel to the left of the steering wheel.

The head/park lamp switch controls the following lighting systems:

• | The headlamps

• | The taillamps

• | The park lamps

• | The side marker lamps

• | The instrument panel lamps

• | The courtesy lamps

The automatic ON/OFF exterior lighting control is available with twilight sentinel. An audible alarm warning is wired into the headlamps control system. The audible alarm warning sounds a chime if the following conditions exist:

• | The head/park lamp switch is in the PARK or The HEAD position

• | The ignition key is turned to 1 of the following positions:

- | OFF

- | LOCK

- | ACCY