Golf GTI L4-1984cc 2.0L DOHC (9A) (1990)
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 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.