Operation CHARM: Car repair manuals for everyone.

Air Flow Sensor Plate Position Sensor: Service and Repair


1. Remove the intake air boot.

Air Flow Sensor Plate Potentiometer Location:





2. Remove the potentiometer harness connector.

Air Flow Sensor Plate Potentiometer Adjustment:





3. Remove the potentiometer mounting screws and carefully lift out the potentiometer.
4. Install the new potentiometer; leave the mounting screws loose enough to adjust the potentiometer.

Air Flow Sensor Plate Test Connection:





5. Install test harness VW 1501 or equivalent between the potentiometer electrical plug and the CIS-E harness connector.
6. Switch the ignition "ON".

Air Flow Sensor Plate Adjustment:





7. Lift the air flow sensor plate until it is flush with the narrowest point in the air cone. Maintain this position.
8. Connect a suitable volt/ohm meter between terminal 2 and 3 of the test harness. (If the harness is not available connect the meter between terminal 2 and 3 of the potentiometer plug).
9. Adjust the potentiometer position to obtain 0.2 to 0.3 volts and secure the mounting screws.
10. Raise the air flow sensor plate to it highest position.

^ The voltage should increase to approx. 7 volts.

If the correct measurement is not obtained, check the rest position of the sensor plate, Refer to FUEL SYSTEMS and repeat the adjustment procedure.