Adaptive Front Lighting System

Adaptive Front Lighting System

DESCRIPTION

Introduction
The Adaptive Front lighting System (AFS) improves driver visibility under differing driving conditions. AFS provides a larger visible area which is illuminated when cornering by adjusting the position of the beam distribution on the road. Horizontal adjustment is made automatically to the most suitable orientation for the driving conditions using steering angle information and information from other vehicle sensors.

AFS is only available with Xenon headlamps, and also includes dynamic headlamp levelling. The AFS is controlled by the AFS control module, which receives messages from various systems via the high speed CAN bus.

The AFS has four modes of operation:
^ Manoeuvring mode
^ Normal driving mode
^ High speed mode
^ Reverse mode.

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 11E (C0632) on an R wire. Fusible link 11E is located in the Battery Junction Box (BJB) (C0570) and is connected to the ignition switch (C0028) by an N wire. When the ignition switch is in the 'ignition' position, current flows across the switch (C0028) to the following on a Y wire:
^ Fuse 27P
^ Fuse 56P
^ Fuse 61P
^ Fuse 62P
^ The Central Junction Box (CJB).

Fuse 27P (C0583) provides an ignition feed to the AFS control module (C2193) on an RO wire. Fuse 56P (C0582) provides an ignition feed to the LH headlamp actuator (C0009) on an RB wire. Fuse 61P (C0582) provides an ignition feed to the RH headlamp actuator (C0011) on an RO wire. Fuse 62P (C0582) provides an ignition feed to the lighting control switch (C0041) on an NP wire.

AFS Control Module
The AFS control module (C2193) will not initiate the system until it receives an engine running signal. This is supplied by the Engine Control Module (ECM) (C0635 on petrol vehicles, C0411 on diesel vehicles) via the high speed CAN bus on YN (high) and YB (low) wires.

The AFS control module (C2193) also receives the following signals via the high speed CAN bus to enable it to control the system:
^ Steering angle from the steering angle sensor (C0862).
^ Vehicle speed from the ABS module (C0506).
^ Low beam status from the instrument cluster (C0230)
^ Suspension height from the air suspension control module (C0867)
^ Gear position from the transfer box control module (C1854)
^ Engine cranking from the ECM (0635 on petrol vehicles, C0411 on diesel vehicles)
^ Odometer value from the instrument cluster (C0230)
^ Exterior/Interior temperature from the instrument cluster (C0230).

NOTE: The Odometer value and exterior/interior temperature signals are used for diagnostic purposes only.

Using this information, the AFS control module continually adjusts the beam alignment of the headlamps to the optimum condition.