Pedal Position Sensor (PWG)

OPERATION
The Electronic Throttle Control (EML) control unit supplies the pedal position sensor with a controlled voltage of 5V. As regards electrical functions, the pedal position sensor contains a potentiometer. a switch for monitoring the potentiometer, the kick-down switch and a switch for the extemal safety circuit.

CAUTION! The 5V component supply voltage coming from the EML control unit is not shortcircuit proof.

The potentiometer of the pedal position sensor divides the voltage dependent upon the angle of rotation.The part voltage fed back by the potentiometer is converted in an analog/digital converter into a form which can be processed by the microprocessor and converted into angle degrees. The valid angle range is from approx. -5 deg. to approx. 87 deg..

The EML control unit perlorms a switching range check in that it compares the switchon point of the switch (approx. 9 deg.) with the angle setting of the Pedal Value Sender (PWG) potentiometer. If the EML control unit finds that the deviation is too great, the output is limited and the EML warning lamp lights.

A kick-down switch integrated in the pedal position sensor (PWG) is used for detecting "kick-down disengaged" in vehicles with automatic transmission. The switch closes at approx. 74 deg.

The switch for the external safety circuit opens at approx. 2.5 deg. The switch output is connected in series with a diode and arranged externally.