Lighting Control

EXTERIOR LIGHTING CONTROL
The headlamps and park lamps are controlled by external relays which are controlled by the body control module. The headlamp relays are located in the power distribution center and the parklamp relay is located in the micro relay center behind the glove box. When the park lamp switch is turned ON (signals as a ground) the BCM then grounds the park lamp relay to provide power to the park, tail and marker lamps. The park lamp power feed, which is controlled by the BCM, also provides back-up power to the BCM. In the event that the ignition is turned off with the park lamps still on, the BCM will function normally (as if the IOD had been reconnected) until the park lamps are turned OFF. When the headlamp switch is turned ON, (signals as a B+ feed) the BCM grounds low beam and high beam headlamp relay coils to turn ON the headlamps. However, the high beams will not turn ON until the dimmer switch is activated.

Headlamp Time Delay
The headlamp delay feature keeps the headlamps on for 60 seconds, giving the driver and passenger security when exiting the vehicle. It is activated by sequentially turning OFF the ignition, and then turning off the headlamps. The headlamps must be turned OFF within 45 seconds of the ignition transition to off, to activate the headlamp delay. Once the headlamp delay has started the headlamps will remain on for 60 seconds or until the park lamps (or headlamps) are cycled ON/OFF or the ignition is turned ON.

Battery Protection
If the park lamp or headlamp switch remains on for more than 3 minutes while the ignition is OFF, the headlamps and park lamps will be turned OFF by the BCM and the input causing the lamps to be on will be ignored until the condition is corrected. Once the 3 minute timeout has elapsed the BCM will enter sleep mode. This feature provides protection to avoid running the battery down in the event the customer fails to turn the lamps OFF.

INTERIOR LIGHTING CONTROL

Courtesy Lamp Control
The interior courtesy lamps located in the right and left foot well area, the rear view mirror and the ignition switch halo lamp are hardwired together and are controlled by the BCM. They can be activated by the dome lamp switch, by opening a door or by the RKE when it activates the BCM 30 second illuminated entry timer. The interior lamps will then fade to off over a 5 second period.

Reading Lamps
The reading lamps and control switches are mounted on the rear view mirror.

Interior Lamp Battery Protect Feature (Load Shedding)
To protect the battery from excessive current draw, the courtesy, halo, reading and glove box lamps are shut off after 15 minutes if they have been left ON or a door has been left ajar after the ignition key is removed from the ignition. This is accomplished by the BCM which removes ground from these lamps.

Instrument Panel Dimming
I/P dimming is accomplished using the body control module. The panel dimming level switch is read by the body control module and converted to a value that is sent over the CCD bus.

I/P Dimmer/Dome Lamp Switch
This switch is part of the headlamp switch. It is used to adjust the intensity of the instrument panel lighting. Instrument panel dome lamps can be requested by rotating the I/P illumination switch fully counterclockwise.

Illuminated Entry
Illuminated entry will be initiated when the customer enters the vehicle by unlocking the doors with the key fob, or with the key or by opening any door. Upon exiting the vehicle, if the lock button is pressed with a door open, illuminated entry will cancel when the door closes. If the vehicle is secure, and a remote keyless entry lock message is received, illuminated entry will cancel. If the doors are closed and the ignition switch is turned ON, the illuminated entry also cancels.