Audi 243 Service Manual page 24

System components
For technical reasons, the voltage for the left-
hand level sensors (front left G78 and rear left
G76) is supplied by the headlamp range
control unit J431. Power is supplied to the
right-hand level sensors (front right G289 and
rear right G77) by the 4-level air suspension
control unit J197.
This ensures that if control unit J197 fails, the
headlamp range control system can continue
to operate (see also Self-levelling control unit
page 34)
Level sensor on rear axle
243_033
24
Pin assignment for the level sensor
Pin
1 Earth
(left from J431, right from J197)
2 Vacant
3 Vacant
4 Analogue signal output,
Voltage signal
(left only for HRC)
5 5 Volt power supply
(left from J431, right from J197)
6 Digital signal output,
PWM signal
(right and left for J197)
J431 Control unit for
HeadampRangeControl
J197 Self-levelling suspension control unit
Level sensor installation
position
243_037