L322 Range Rover System Description and Operation
ENGINE MANAGEMENT SYSTEM – V8
DESCRIPTION AND OPERATION 18-2-17
Accelerator Pedal Position (APP) Sensor
1 Detente mechanism
2 Sensor spigot
3 Pedal
4 Springs
5 Cables
6 Bush
7 Drum
8 APP sensor
The APP sensor is located in a plastic housing which is integral with the throttle pedal. The housing is injection
moulded and provides location for the APP sensor. The sensor is mounted externally on the housing and is secured
with two Torx screws. The external body of the sensor has a six pin connector which accepts a connector on the
vehicle wiring harness.
The sensor has a spigot which protrudes into the housing and provides the pivot point for the pedal mechanism. The
spigot has a slot which allows for a pin, which is attached to the sensor potentiometers, to rotate through
approximately 90
°
, which relates to pedal movement. The pedal is connected via a link to a drum, which engages with
the sensor pin, changing the linear movement of the pedal into rotary movement of the drum. The drum has two steel
cables attached to it. The cables are secured to two tension springs which are secured in the opposite end of the
housing. The springs provide 'feel' on the pedal movement and require an effort from the driver similar to that of a
cable controlled throttle. A detente mechanism is located at the forward end of the housing and is operated by a ball
located on the drum. At near maximum throttle pedal movement, the ball contacts the detente mechanism. A spring
in the mechanism is compressed and gives the driver the feeling of depressing a 'kickdown' switch when full pedal
travel is achieved.
