Passat L4-1984cc 2.0L DOHC (9A) (1990)
Air Flow Meter/Sensor: Description and Operation
Air Flow Sensor Potentiometer
Air Flow Sensor Plate Potentiometer
The air-flow sensor plate potentiometer which is located on the air flow sensor housing provides the CIS-E Motronic control unit with information
concerning engine load. The potentiometer consists of a wiper brush working on a carbon film.
Potentiometer Voltage Graph
The E.C.U. provides the air-flow sensor plate potentiometer with a 5 volt reference signal. As air flow increases the sensor plate provides a modified
voltage signal back to the E.C.U. via the potentiometer wiper. This input to the E.C.U. is used to control ignition timing, acceleration, and full-throttle
enrichment.