GF82.10-P-1001QB Headlamp Range Adjustment (HRA) Headlamp Function

GF82.10-P-1001QB Headlamp Range Adjustment (HRA) Headlamp Function
- up to 1.12.04
- with CODE (614) Bi-xenon headlamp unit

- Model 209.3/4
- with CODE (615) Bi-xenon headlamp unit with integrated curve illumination

Component Identification:

The electric headlamp range adjustment is prescribed by law to prevent dazzling oncoming traffic. The headlamp range control automatically maintains the inclination angle of the headlamps within the legally defined limits regardless of the vehicle load

Function requirements:
^ Circuit 15 ON
^ Rotary light switch (S1s1) in "Driving lamps ON" position
^ Rotary light switch (S1s1) in "AUTO" position and the rain/ light sensor (B38/2) has detected "Night"
^ In the instrument cluster (A1), daytime running lamps are active

Function
The data from the headlamp range adjustment rear axle sensor (A51) and headlamp range adjustment front axle sensor (A52) are read in by the headlamp range adjustment control unit (N71).

Moreover, data are received via the Controller Area Network bus class C (engine compartment) (CAN-C), which are required for calculating the adjustment request. The evaluation of the wheel speed signals enables the headlamp range adjustment control unit (N71) to determine whether the vehicle is traveling at a constant speed, is accelerating or is being braked. The headlamp range adjustment control unit (N71) passes on the adjustment request to the xenon headlamp control unit (E2n1) and to the xenon headlamp control unit (E1n1). The xenon headlamp control unit (E2n1) actuates the right headlamp range adjustment motor (E2m1) and the xenon headlamp control unit (E1n1) actuates the left headlamp range adjustment motor (E1m1). The headlamp range adjustment motors feed their relevant positions back to the control units via internal potentiometers.

At a constant vehicle speed, the electric headlamp range adjustment operates in "static mode" with a low motor adjustment rate. If, however, positive or negative vehicle acceleration is occurring, the change is performed in "dynamic mode" at a high rate of adjustment.