Dynamic headlight range control

General information

Dynamic headlight range control (HRC) holds the tilt angle of the light constant even when the vehicle tilt varies due to a change of loading or during acceleration or braking. The headlight range control receives the vehicle tilt information from the air suspension (over the CAN bus).

On vehicles with the Advanced Frontlighting System, the cornering lights are switched on or off according to the driving conditions.

Dynamic headlight range control

Adaption of dynamic headlight range control

The headlight range control may only be adapted as per the factory setting.

Factory setting:

            Adaption channel 1:       4

            Adaption channel 2:       1

            Adaption channel 3:       0

            Adaption channel 4 (if present):  0

When an adaption is carried out, the basic setting must be carried out afterwards.

The basic setting must be performed after replacing

J a headlight,

J an axle sensor or

J the control unit,

or after performing an adaption.

Basic setting procedure:

J The headlights are moved to the alignment position.

J Then you must align the headlights.

J The control unit now learns this position as the default.

Measured value blocks for the headlight range control unit -J431:

Measured value block 1:

1. Voltage terminal 15

2. Lights (term. 56b) (on/off)

3. Vehicle speed

4. Vehicle acceleration

Measured value block 2:

1. Sensor value, front

2. Sensor value, rear

3. Control motor activation (stepper motor position)

4. Control motor control speed

Measured value block 3:

1. CAN signal turn signal left (on/off) (The signal flash frequency does not change between on and off, but remains permanently on when the signal is activated.)

2. CAN signal turn signal right (on/off) (The signal flash frequency does not change between on and off, but remains permanently on when the signal is activated.)

3. CAN signal brake (on/off)

4. CAN signal engine (on/off)

Measured value block 4:

1. Cornering light right (on/off)

2. Cornering light left (on/off)

3. Cornering light high brightness right (on/off)

4. Cornering light high brightness left (on/off)

Measured value block 5:

1. CAN signal steering angle sensor (on/off)

2. -

3. -

4. -

Measured value block 125:

1. Communication with brake control unit

2. Communication with Gateway

3. Communication with power steering control unit

4. Communication with engine control unit

Measured value block 126:

1. Communication with self-levelling suspension control unit

2. -

3. -

4. -

Measured value block 225:

1. Counter for EMC faults in communication with brake control unit

2. Counter for EMC faults in communication with Gateway

3. Counter for EMC faults in communication with steering angle sensor

4. Counter for EMC faults in communication with engine control unit

(EMC = ElectroMagnetic Compatibility)

Measured value block 226:

1. Counter for EMC faults in communication with self-levelling suspension control unit

2. -

3. -

4. -

Coding, headlight range control unit -J431 with AFS

The following coding is possible:

0000018 = Headlight range control, automatic/dynamic with cornering lights and (PR adaptive light function (AFS2) (PR number 8Q6)               

YZ Note

J AFS = Advanced Front lighting System

JThe coding is protected by a Security Access stage.

Headlight module for AFS