Accelerator Pedal Position Sensor: Description and Operation

Accelerator Pedal Value Sender:

Accelerator Pedal Arrangement:

PURPOSE
Pedal position information is supplied to the Electronic Throttle Control (EML) control unit by the accelerator pedal position sensor.

Pedal Value Sender:

OPERATION
The pedal position sensor contains a potentiometer, monitoring switch, and an external safety circuit switch. The potentiometer (voltage divider) of the pedal position sensor divides a 5 volt reference voltage (from the EML), indicating the angle of rotation. This partial voltage is fed back to the EML where the analog signal is converted into digital "angle" degrees. The valid angle range is from -4.7° to +100.8°.

The EML control unit performs a range check by comparing the "switch ON" state of the monitoring switch to the angle setting of the pedal position sensor. If the EML determines that the difference is too great, output to the throttle position motors is limited and the EML warning light is illuminated.

Transmission "kick-down" is engaged when the pedal position angle is greater than 70°. The switch for the external safety circuit opens at approximately 2.5°. When the accelerator pedal is released and the brake pedal is depressed, both DME control units receive a "closed throttle" signal from the safety switch.