LR3/Disco 3
The seat position sensor allows the RCM (restraints control module) to detect when the driver seat is forward of a given
point on the seat track. The seat position sensor consists of a Hall effect sensor attached to the driver seat frame and a
target plate on the seat base. While the ignition is on, the RCM (restraints control module) supplies the sensor with a
power supply of 12V nominal, and monitors the return voltage. When the seat frame moves forwards, the sensor moves
over the target plate, which changes the reluctance of the sensor. The change of voltage is detected by the RCM
(restraints control module) and used as a switching point. The switching point is when the center of the sensor is 3 ± 4
mm from the leading edge of the target plate.
When the driver seat is forward of the switching point, the RCM (restraints control module) increases the time delay
between firing the two stages of the inflator in the driver air bag. When the driver seat is rearward of the switching point,
the RCM (restraints control module) uses the normal time delay between firing the two stages.
SRS WARNING INDICATOR
Item Part Number
Description
1
-
Seat frame
2
-
Mounting plate
3
-
Seat position sensor
4
-
Electrical connector
5
-
Target plate
6
-
Seat base
