GM Service Manual Online
For 1990-2009 cars only

Headlamps

The headlamps can be turned on three different ways:

    •  When the headlamp switch is placed in the ON position.
    •  The twilight sentinel feature.
    •  The wiper activated headlamps feature.

If the headlamp switch is left in the ON position, the headlamps will be deactivated after 10 minutes following an ignition switch transition to the OFF position because of the battery rundown protection feature. If the headlamp switch is turned on with the ignition switch in the OFF position, the headlamps will remain on until the headlamp switch is turned off or the battery runs down. When the headlamps or the park lamps are on, the LIGHTS ON indicator will illuminate.

A HEADLAMPS SUGGESTED message will appear on the driver information center (DIC) when the headlamps and park lamps are off due to all exterior lighting controls being inactive when nighttime conditions are sensed.

When the low beam headlamps are on, the headlamps can be switched to the high beams by pulling the turn signal lever all the way toward you and releasing. The high beam indicator will also illuminate. When the turn signal indicator is pulled toward you and released again, the headlamps will then switch to the low beams from the high beams.

Wiper-Activated Headlamps

The wiper-activated headlamps feature activates the headlamps and park lamps after the wipers have been activated for 20 seconds. The twilight sentinel must be turned on in order to operate the wiper-activated headlamps. If the twilight sentinel and the headlamps are off, but the windshield wipers are on, the HEADLAMPS SUGGESTED message will appear on the driver information center (DIC) when the headlamps and park lamps are off due to all exterior lighting controls being inactive when nighttime conditions are sensed.

Twilight Sentinel

The twilight sentinel is a convenience system that controls the operation of the exterior lamps in response to the level of ambient light. It turns on and off the headlamps depending on whether nighttime or daytime conditions are sensed. It will also keep the exterior lamps on for a pre-selected period of time after the ignition is turned to the OFF position with nighttime conditions sensed. The exterior lamps will be turned off automatically after the delay period elapses. The delay period ranges from a few seconds to 3 minutes in 10 second increments.

Daytime Running Lamps

The daytime running lamps (DRL) illuminate the high beam headlamps at a reduced intensity. The DRL will operate when the ignition switch is in the ON or START position and the gear selector lever is out of the PARK position. Any function that turns on the headlamps will override and disable the DRL system.

Flash-To-Pass

When the headlamp dimmer switch is pulled toward the driver, the high beam headlamps will illuminate as long as the switch is held. This will occur in both the off, and the DRL mode. If the low beams are on, the headlamps will shift to high beams and stay there.

Fog Lamps

The fog lamp switch is a momentary switch that changes the fog lamp state from off to on or from on to off when pressed. The state of the fog lamps will remain the same until the fog lamp switch is pressed, even between ignition cycles. The fog lamps operate only when the ignition switch is in the ON or START position and the fog lamp state is on. The fog lamps will not illuminate when the high beam headlamps are on. When the fog lamps are on, the park lamps will also be activated. The fog lamp indicator will also illuminate.

Perimeter Lighting

Perimeter Lighting involves activating the vehicle's park lamps, tail lamps, and low beam headlamps for 20 seconds after the driver's door is unlocked using the keyless entry transmitter. The perimeter lighting feature can only be used under the following conditions:

    • Perimeter lighting has been enabled through the Driver Information Center (DIC).
    • Nighttime conditions are sensed.
    • The park lamps are off.

The lamps will remain on until a door is opened or the key is turned to the ON position.

Perimeter lighting can be programmed to be either enabled or disabled for all drivers of the vehicle through the driver information center (DIC) if the vehicle does not have the personalization option. Perimeter lighting can be programmed to be either enabled or disabled for each driver of the vehicle through the driver information center (DIC) if the vehicle has the personalization option.

Park Lamps

The park lamps will illuminate when the headlamp switch is placed in the PARK or ON position. If the headlamp switch is left in the PARK or ON position, the park lamps will be deactivated after 10 minutes following an ignition switch transition to the OFF position, because of the battery rundown protection feature. The park lamps will also illuminate if the fog lamps are activated. When the park lamps are on the LIGHTS ON indicator will also illuminate.

Turn Lamps

The turn lamps can only be activated with the ignition switch in the ON or START position. When the turn signal switch is placed in a position to indicate a left turn or a right turn, the respective turn lamps will flash. The respective turn indicator will flash on the instrument cluster (IPC).

Cornering Lamps

When the ignition switch is in the ON or START position and the turn signal switch is placed in a position to indicate a left turn or a right turn, the appropriate cornering lamp will illuminate.

Hazard Lamps

When the hazard switch is pressed, all turn lamps and the hazard switch will flash. When the ignition switch is in the ON position both turn indicators will flash on the instrument cluster (IPC).

Stop Lamps

When the brake pedal is pressed, all stop lamps and the high mount stop lamp illuminate. The hazard lamps and turn lamps override the stop lamp operation, except for the high mount stop lamp.

Backup Lamps

When the ignition switch is in the ON position and the gear selector lever is in the REVERSE position, the backup lamps illuminate.

Courtesy Lamps

The courtesy lamps can be manually turned on or off by placing the interior lamp switch in the ON or OFF position. When the ambient light sensor indicates nighttime conditions, and a door is opened, all courtesy lamps turn on. After all doors are closed, the courtesy lamps will remain on for approximately 20 seconds. The courtesy lamps will dim to off, if the ignition switch is turned to the ON position, or an all door lock command is received with all doors closed.

When the ambient light sensor indicates nighttime conditions, and the keyless entry transmitter is used to unlock the vehicle, all courtesy lamps turn on for approximately 20 seconds. The courtesy lamps will dim to off, if the ignition switch is turned to the ON position, or an all door lock command is received with all doors closed.

Underhood Lamp

When the hood is opened and the park lamps or the headlamps are on, the underhood lamp illuminates. The underhood lamp will remain on until the hood is closed or until the park lamps are turned off.

Rear Compartment Lamp

When the rear compartment lid is opened, the rear compartment lamp illuminates. The rear compartment lamp will remain on until the rear compartment lid is closed or until the battery rundown protection feature activates.

Vanity Lamps

When the vanity mirror cover on the sunshade is opened, the vanity lamp illuminates. The vanity lamp can be dimmed through sliding switch next to the mirror.

IP Compartment Lamp

When the IP compartment is opened, the IP compartment lamp illuminates. The IP compartment lamp will remain on until the IP compartment door is closed or until the battery rundown protection feature activates.

Interior Lamps Dimming

When the ignition switch is in the ON position, the vacuum fluorescent (VF) displays turn on at maximum brightness. When the park lamps are on and the ambient light sensor indicates nighttime conditions, all of the incandescent backlighting turn on at the dimming level indicated by the IP dimmer switch, and all VF displays dim to match the dimming level indicated by the IP dimmer switch. When the IP dimmer switch is moved from MIN to MAX, all VF displays and incandescent switch backlighting dimming level goes from minimum intensity to maximum brightness in response to the IP dimmer switch.