Adaptive Front Lighting System

The Adaptive Front Lighting System (AFLS) incorporates an Adaptive Front Lighting Module (AFLM) that monitors hardwired inputs from the front and rear axle leveling sensors as well as Controller Area Network-Chassis (CAN-C) bus inputs to provide two features of the AFLS:

1. Dynamic Bending Light (DBL)

   - The DBL feature consists of a horizontally swivelling low beam. The swivelling depends on various parameters relating to vehicle dynamics. The DBL feature will only function when the vehicle is in a forward gear.

2. Automatic Vertical Aim Control (AVAC)

   - The AVAC feature automatically corrects the illumination distance of the headlights when the low beam lamps are turned on. The AVAC ensures sufficient depth of vision for the driver. The influence of the vehicle body tilt on the illumination distance is compensated relative to the road service.

The DBL and AVAC functions are activated and deactivated by a soft button located in the radio or the Electronic Vehicle Information Center (EVIC). The AFLM will transmit a CAN-C message to the BCM based on the customer selectable option chosen.

The AFLM uses the following inputs and signals to determine how to utilize the leveling and swiveling stepper motors:

• Acquires the front axle position from the front axle sensor
• Acquires the rear axle position from the rear axle sensor
• Acquires the engine status from the PCM over the CAN-C bus
• Acquires the ignition status from the BCM over the CAN-C bus
• Acquires the reverse gear status from the ESM over the CAN-C bus
• Acquires the low beam status from the BCM over the CAN-C bus
• Acquires the vehicle speed signal from the ABS module over the CAN-C bus
• Acquires the steering angle from the EPS unit over the CAN-C bus
• Acquires configuration signals from the BCM over the CAN-C bus

Each headlight contains four stepper motors that are each a Local Interface Network (LIN) slave node to the AFLM. These stepper motors respond to AFLM commands by adjusting the aim of the headlight beams up, down, right or left.

The AFLM performs the following to drive the DBL swiveling stepper motors:

• Calculates a setpoint for the swivel angle of each headlight based on a speed dependent logic.
• Transmits the position commands for the DBL stepper motors for both the left and right headlight to the Left Headlight Drive Unit (LFDU) over the LIN bus. Once the LFDU receives the LIN commands, it will actuate the left DBL stepper motors the AFLM will directly actuate the right stepper motor output through a hardwired signal.
• Transmits any fault status of the AFLS to the BCM over the CAN-C bus. The Instrument Panel Cluster (IPC) will acquire this signal and activate the AFLS faults indicators as needed.
• Transmits the activation state of the AFLS system to the BCM over the CAN-C bus

The LHDU acquires the commands provided over the LIN by the AFLM, it will actuate the two left headlight stepper motors.

The AFLM performs the following to drive the AVAC leveling stepper motors:

• Calculates the pitching angle of the vehicle body from the axle position provided by the front and rear axle position sensors.
• Reads the value of the vehicle speed over the CAN-C bus to determine if the vehicle is in constant speed more or acceleration mode.
• Calculates a setpoint for the vertical orientation of the headlight reflectors depending on the pitching angle and its current operation mode, constant or acceleration.
• In constant speed mode, the calculation of the setpoint features high damping and minimal adjustment sped. In acceleration mode, the response time is substantially reduced, On the other hand, if the vehicle is standstill, the AFLM will correct the vertical aiming of the headlights depending on the calculated pitching angle in order to compensate changes of the vehicle loads.
• Transmits the position commands for the AVAC stepper motors for both the left and right headlight to the LFDU over the LIN bus. Once the LFDU receives the LIN commands, it will actuate the left AVAC stepper motors and the AFLM will directly actuate the right stepper motor output through a hardwired signal.
• Transmits any fault status of the AFLS to the BCM over the CAN-C bus. The Instrument Panel Cluster (IPC) will acquire this signal and activate the AFLS faults indicators as needed.
• Transmits the activation state of the AFLS system to the BCM over the CAN-C bus

The LHDU acquires the commands provided over the LIN by the AFLM, it will actuate the two left headlight stepper motors.

The BCM will send bus messages to the IPC to display the appropriate AFLS messages to the driver.