LR3/Disco 3
The rain/light sensor is located at the upper edge of the windscreen, behind the interior rear view mirror. The sensor is
mounted on an optical unit, which is heat bonded to the inner surface of the windscreen during manufacture. If damage
occurs to the optical unit or the windscreen, then a new windscreen will be required and installation can only be
performed by an authorised Land Rover dealer.
The rain sensor must be re-initialised to a new windscreen, if fitted, or if transferred to another vehicle, the new rain
sensor assembly will automatically re-initialise when powered-up for the first time. In order for this to occur successfully it
must be fitted and connected to the optical filaments (bonded to the screen assembly).
The rain/light sensor unit attaches to the optical unit via two clips, which latch onto formed tags on the optical unit.
Positive retention is achieved by two retaining clips, which force the clips onto the tags. The retaining clips must be
withdrawn to facilitate sensor removal.
The sensor provides information to the CJB for the optimum wiper operation for the prevailing conditions to maintain the
screen in a clear condition at all times. The rain/light sensor is an optical unit, which operates on an infrared waveband.
The sensor uses the principle of the laws of reflection on interfacing surfaces between materials with differing refraction
properties.
Rain Sensor Functionality
4
Heater
5
Housing
6
Locking device
7
Printed Circuit Board (PCB)
8
Screws
9
Cover
10
Contact pins
Item Part Number
Description
A
Clean and dry windscreen
B
Wet and dirty windscreen
1
Windscreen - Outside surface
2
Optical unit
