L322 Range Rover System Description and Operation
WIPERS AND WASHERS
84-14
DESCRIPTION AND OPERATION
The light is reflected four times from when it leaves the transmitter diodes to when it is picked up by the receiver
diodes. If the windscreen is wet or dirty in the area of the optical unit, the clean conditions for 100% reflection means
that some of the light reflected is lost. As the screen becomes dirtier or wetter, the received light is evaluated by the
rain sensor and translated into a signal value. A micro-controller within the sensor monitors the change in signal and
initiates the appropriate wipe cycle via K bus signals to the BCU.
The software can compensate for the long term effects of scratches and stone chips in the area of the optical unit and
the short term effects of dirt or smears caused by worn wiper blades. A heater element is also contained within the
rain sensor and uses ambient temperature K bus signals from the instrument pack to keep the optical unit clear of
frost or condensation.
A light sensor is incorporated into the sensor and is used to increase the sensitivity of the sensor when light levels are
low. This feature counteracts the effects of rain on the windscreen affecting the driver's vision during night time driving.
Rear Wiper
The rear wiper system comprises:
l
Wiper motor and control module assembly
l
Rear washer pump
l
Wiper arm and blade.
Wiper Motor
1 Harness connectors and control module
2 Washer fluid hose connection
3 Mounting bracket
4 Non-return valve (NRV)
5 Motor
6 Wiper blade
7 Wiper arm
8 Torx head screw (3 off)
The rear wiper and washers operation is controlled by the control module which is located with the rear wiper motor.
The rear wiper operation is remote from the BCU control of the front wiper systems.