Headlamp Control Module: Specifications

Component specification, Gas Discharge Lamp Module (GDL)

Front axle sensor and rear axle sensor

General




The sensors sense the angle of the vehicle at different loads and send the information to the "master" of the two Gas Discharge Lamp Modules (GDLs). The "master" Gas Discharge Lamp Module (GDL) then sends control signals to the motors that regulate the beam length.

Type
Resistance sensor.

Characteristics
The resistance between connections 1 and 4 changes linearly depending on the angle.

Other information
One of the position sensors is located next to the rear axle and is connected to the left rear control arm via a link system. The other position sensor is located next to the right front axle and is connected to the right front control arm via a link system. The vehicle's angle is measured by the sensors being affected via the relevant link system.

connection















Check
Conditions (unless otherwise specified):
- Sensor connected.
- Ignition position II.

Check 1
Position sensor:
Measure the direct voltage between connections 1 and 4. The value must be: Uapproximately1.5-3.8 V in ignition position II.

GDL-Master and GDL-Slave

General




There are two Gas Discharge Lamp Modules (GDLs), one for each headlamp. The one located on the driver's side of the vehicle acts as "master" and communicates with the Central electronic module (CEM) via LIN-communication. The other Gas Discharge Lamp Module (GDL)acts as "slave" and communicates with the "master" control module via LIN-communication.

Other information
An electronic ballast is connected to each headlight. The ballast acts as a voltage regulator and generates alternating voltage (AC).

connection










Check

Check 1
Checking the power supply to Gas Discharge Lamp Module (GDL)
Conditions (unless otherwise specified): Ignition off.
- Connect the breakout box for the Central electronic module (CEM).
- Ignition on.
- Light switch in position 2.
Take readings between:
- Central electronic module (CEM) #E1 (#1) and ground.

Hint: This output powers both the left and right Gas Discharge Lamp Module (GDL).

The power supply to the Gas Discharge Lamp Module (GDL) must be 12 V and must not exceed 19 V.