Automatic Dynamic Headlight Range Control (Lwr); Task - Volkswagen PASSAT - YEAR 2001 Manual

The Electrics

Automatic dynamic headlight range control (LWR)

The Passat 2001 with BI-xenon headlights has automatic headlight range control.

Task

The task of the automatic headlight range control
is to adjust the headlights to compensate for
variation in ride height as a function of payload.
The headlight range control system comprises:
Vehicle "level"
senders
G76
and G78
Road speed signal
Function:
Headlight range control, control unit J431
receives signals from two level sensors (one on
the front axle and one on the rear axle) and the
road speed signal. Having evaluated the signals,
the system activates the control motors in the
headlights and thereby compensates for
variation in vehicle level.
42
Terminal 15
Terminal 31
Terminal 56
Headlight range control,
control unit J431
in the luggage
compartment, left
Self-diagnosis
Input signal
Output signal
The automatic headlight range control also
compensates for variation in headlight range
caused by dynamic effects under braking and
acceleration, for example.
stepping motor, right
V49
stepping motor, left
V48
+
Earth
The headlight control motors are configured as
stepping motors. They can perform the full range
of headlight adjustments within approximately 1
second.
The control unit has self-diagnostic capability
and can be addressed with address word 55.
251_004