Headlamp Range Adjustment, (HRA) Function

Component Identification:

NOTE: When equipped with ADS the front axle level sensor (B22/2) and the rear axel level sensor (B22/3) take over the function of the front axle and rear axle sensors (headlamp range adjustment) (A52 and A51).

Component Identification:

S��aModel 210 With Code (612b):

Electric headlamp range adjustment (with xenon headlamps)
The electric headlamp range adjustment operates dynamically. The rear axle and front axle sensors (A51, A52) sense every change in the vehicle level and send a corresponding signal to the headlamp range adjustment control module (N71). The control module (N71) compares the vehicle level and the headlamp position. If applicable, the control module (N71) corrects the headlamp range adjustment via the headlamp range adjustment motor (E1m1, E2m2). The headlamps are only adjusted when the rear axle and front axle sensors (A51, A52) signal a change in the vehicle level to the control module (N71) over a certain period of time.

Headlamp range adjustment control module (N71)
The control module (N71) processes the signals from the front axle/rear axle sensors (A51, A52) and the position of the headlamp range adjustment motor (E1m1, E2m1). After evaluating the signals it transmits commands to the headlamp range adjustment motors (E1m1, E2m1) if applicable.

Front and rear axle sensors (A51, A52)
One sensor each is installed on the front and rear axle torsion bars. These sensors (A51, A52) transmit a signal to the control module (N71) corresponding to the vehicle level.

Headlamp range adjustment motor (E1m1, E2m1)
A potentiometer in the motor signals the position of the reflectors to the control module (N71). The motors (E1m1, E2m1) receive a command from the control module (N71) to correct the headlamp adjustment. When the low beams are switched on and the key is in position "two" the motors are "synchronized" for reference. The reflectors are moved to the lowest position and then back to the correct position corresponding to the vehicle level.