Throttle Position Sensor: Description and Operation

Throttle Valve Potentiometer:

AUTOMATIC TRANSMISSION ONLY

The throttle valve potentiometer, which is mounted on the throttle valve housing, provides information to the CIS-E Motronic control unit and the Digimat electronic 4 speed automatic transmission control unit concerning throttle valve position.
When the throttle valve potentiometer is in the closed position (throttle valve closed) a ground circuit is completed and an idle condition is recognized by the CIS-E Motronic control unit. As the throttle valve is opened slightly the circuit is interrupted and a non idle condition is recognized by the CIS-E control unit. This information is used by the control unit to calculate the appropriate values for the operations of idle stabilization, deceleration fuel shut-off, and activation of special ignition timing maps. A full throttle switch is no longer necessary.