Contents: Headlights ↧ Warning light headlights ↧ Parking lights and direction… ↧ Fog lights ↧ Rear combination lights ↧ Additional central brake light ↧ Reversing lights ↧ License plate lighting ↧ Auxiliary Body Controller (XBCM) ↧
Headlights
The headlights are controlled by the multi-function lever on the left side of the steering column. The headlights can be turned on when the ignition switch is in the ON position. If the headlight switch is in the ON position and the ignition key is in the ACC or LOCK position, the headlights are automatically turned off. Moving the headlight switch to the first position will turn on the parking lights, license plate light and instrument panel light. Moving the switch to the second position will turn on all previous lights and the headlights. Moving the switch to the OFF position will turn off all lights.
The headlights can be turned on in 2 different ways. The first way is when the driver sets the headlight switch to the HEADLAMP position for normal operation. The second way is when the headlight switch is set to the AUTO position for Automatic Light Control (ALC). In the AUTO mode, the headlights will be in Daytime Running Light (DRL) mode in daylight conditions and in normal headlight mode in low light conditions.
The headlamps are controlled by the body control module (BCM) by applying a signal to the headlamp switch input circuit when the headlamp switch is in the HEAD position. When the headlamp switch is in the AUTO position, the BCM controls the headlamps on and off based on the voltage from the ambient light sensor.
The same lever is used to switch between low and high beam headlights. When the headlights are on, pressing the lever away from the driver until it clicks will switch from low to high beam. When the high beam headlights are on, the indicator lamp on the instrument cluster assembly will light. To return the low beam headlights, pull the lever towards the driver. The headlights must be adjusted to properly illuminate the road. It is necessary to check the headlight adjustment when installing a new headlight assembly, as well as after repair and maintenance work on the front of the car, during which the position of the headlight assembly or its fasteners may have changed.
Warning light headlights
The ambient light sensor is a light-sensitive transistor that varies a voltage signal to the body control module (BCM) based on the ambient light level. When this signal is received, the BCM either turns on the low beam headlamps in daytime running light (DRL) mode or turns on the low beam headlamps and the outside lamps in automatic lighting control (ALC) mode. Any function or condition that turns on the headlamps will cancel the DRL mode. Thirty seconds after the engine is started, if the headlamp switch is in the OFF position, the DRL function will do one of the following:
- will turn on the low beam headlights at reduced intensity in daylight conditions;
- will turn on the low beam headlights and external parking lights when the outside light level is low.
The DRL function operates when the ignition switch is in the RUN position, the parking brake is not applied, and the transmission is not in the PARK position. When these conditions are met and the DRL ambient light sensor indicates daytime running light, the daytime running light comes on.
Parking lights and direction indicators
The parking lights can be turned on by turning the headlight switch to the first position. The parking lights can be turned off by turning the switch to the off position.
When the direction indicators are turned on, the corresponding direction indicator lights start flashing to indicate a change in direction. The front, rear and side direction indicators only work when the ignition is on.
The front and rear turn signals are controlled using the multi-function lever on the left side of the steering column. The turn signals are activated by moving the lever all the way up or down through the stop. Once the turn is completed, the lever is automatically released and the front and rear turn signals stop flashing.
When changing lanes and making gentle turns, when the steering wheel does not turn far enough to cancel the signal, the signal lever should be moved to the first stop and held in this position. The turn signal stops when the lever is released.
Fog lights
The fog light switch is located on the instrument panel above the audio system. To use the fog lights, first turn on the headlights. Then press the fog light switch. The indicator light in the instrument cluster comes on, indicating that the fog lights are on. To turn off the fog lights, press the switch again. The indicator light goes out.
Fog lights need to be adjusted to properly illuminate the road. Check the adjustment of the fog lights when installing a new bulb, and after repairs or maintenance work on the front of the vehicle that may have changed the position of the fog light assembly or its mountings.
Rear combination lights
The tail lights, brake lights, reversing lights and direction indicators are all part of a single unit.
Turning on the headlights or parking lights will also turn on the taillights. When you press the brake pedal, the taillights will shine brighter and serve as brake lights.
Additional central brake light
The additional central brake light is located on the rear window and lights up when the brake pedal is pressed.
Reversing lights
The reversing lights come on when the transmission is shifted into reverse. On vehicles with an automatic transmission, the reversing lights are activated by the Park/Neutral switch.
License plate lighting
The number plate light is turned on when the headlights or parking lights are turned on. The number plate lights are mounted on the rear end door above the number plate.
Auxiliary Body Controller (XBCM)
Important: Perform SPO reprogramming when replacing the X-BCM. The X-BCM controller is located behind the instrument cluster.
Functioning of the alarm siren controller
The XBCM controller acts as a master controller when communicating with the alarm siren controller. The XBCM controller activates, deactivates and turns on the alarm depending on the current state of the CTD or VTD anti-theft system. The XBCM controller receives commands via signals from GMLAN, which determine the current state of the vehicle.
Additional CTD (Content Theft Deterrent) Sound Function
The XBCM controller provides control of the additional CTD horn relay.
Rear brake light and turn signal failure detection function
According to the current regulations, the direction indicator system must be equipped with a function to detect a failure of one or more lamps. To do this, the XBCM controller monitors the left and right rear brake lights and direction indicators separately to detect a failure of the brake lights or direction indicators.
Original version of the article on the website «chevyman.ru»