Headlamp Control Module: Description and Operation

GF82.10-P-2020RD Headlamp Control Unit, Component Description
MODEL 172.4
- with CODE (615) Bi-xenon headlamp unit with integrated curve illumination
- with CODE (621) Intelligent Light System (left-hand traffic)
- with CODE (622) Intelligent Light System (right-hand traffic)





N71/1 Headlamp control unit

Location
The headlamp control unit is located at the left A-pillar behind the instrument panel.

Task
The headlamp control unit performs the following:
^ Reading in of sensors, pickups and signals
^ Evaluation of input factors
^ Controlling functions
^ Actuation of components

Reading in of sensors, pickups and signals
The input factors are read in via the following connections:
^ Direct line
^ Front end CAN (CAN G)

Direct line
The signals of the following components are read in by the headlamp control unit on vehicles without code (483) ADVANCED AGILITY package) via a direct line:
- Left rear level sensor (B22/7)
- Left front level sensor (B22/8)

Front end CAN
The signals are read in by the headlamp control unit over the front end CAN.
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
On vehicles with code (483) ADVANCED AGILITY package, the information on the vehicle level is sent by the adaptive damping system control unit (N51/5) via chassis CAN (CAN E).

Evaluation of input factors
The input factors are evaluated by the microprocessor and the corresponding components are actuated.

Controlling functions
The following functions are realized by actuating the appropriate components:
- Automatic headlamp range adjustment (HRA [LWR])
- Low beams power control
- Turning lamps
- Dynamic curve illumination
- In addition with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic):
- Active light distribution

Actuation of components
The actuation of the components takes place via the following connections:
^ Direct line
^ Local Interconnect Network (LIN)

Direct line
The following components are actuated via a direct line:
- Left cornering light (E1e9)
- Right cornering light (E2e9)

LIN
The headlamp control unit actuates components in the left front lamp unit (E1) via left headlamp LIN (LIN G1):
- Left headlamp range adjustment actuator motor (E1m1)
- Left active curve illumination actuator motor (E1m2)
- Left light distribution actuator motor (E1m3) (as of 1.6.12)
- Left xenon light power supply module (E1n4)
The headlamp control unit actuates components in the right front lamp unit (E2) via right headlamp LIN (LIN G2):
- Right headlamp range adjustment actuator motor (E2m1)
- Right active curve illumination actuator motor (E2m2)
- Right light distribution actuator motor (E2m3) (as of 1.6.12)
- Right xenon light power supply module (E2n4)