LR3/Disco 3
measurement from the safety belt tension sensor is used to produce a correction factor for the load measurement from
the pressure pad. The tightness of the safety belt affects the load acting on the pressure pad, so without the correction
factor the occupant classification module cannot derive an accurate occupancy status.
The occupant classification module translates the load readings into a seat occupancy status and transmits the result to
the RCM (restraints control module) , on a dedicated high speed CAN (controller area network) bus link. The occupant
classification module incorporates two load limits for the seat cushion: When the load exceeds the lower limit, but is less
than the upper limit, the occupant is classified as small; when the upper limit is exceeded, the occupant is classified as
large.
The occupant classification system has four possible states:
Empty. Passenger air bag operation is disabled and the passenger air bag deactivation indicator remains off.
Occupied inhibit. The seat is occupied by a small person. Passenger air bag operation is disabled and the
passenger air bag deactivation indicator is illuminated.
Occupied allow. The seat is occupied by a large person. Passenger air bag operation is enabled and the
passenger air bag deactivation indicator remains off.
Error. There is a fault with the system. Only stage 1 (slowest deployment speed) passenger air bag operation is
enabled and the passenger air bag deactivation indicator remains off.
Occupant Classification Module Harness Connector C0962
Occupant Classification Module Harness Connector C0962 Pin Details
SEAT POSITION SENSOR
Pin No.
Description
Input/Output
A
Safety belt tension sensor signal
Input
B
Safety belt tension sensor reference voltage
Output
C
Safety belt tension sensor ground
Input
D
Module ground
Output
E
High speed CAN (controller area network) bus high Input/Output
F
High speed CAN (controller area network) bus low Input/Output
G
Ignition power feed
Input
H
Seat cushion pressure sensor ground
Input
J
Seat cushion pressure sensor reference voltage
Output
K
Seat cushion pressure sensor signal
Input
