Throttle Position Sensor: Description and Operation

Fuel Rack Position Sensor (Y23/1I1)






Design


Position
Integrated in fuel metering control housing of IFI in-line injection pump (10).

Task
Detecting the control travel of the fuel rack. Supplying signal regarding fuel rack travel and position to the IFI control module (N3/7).







Function

Start
With ignition "ON" (depending on coolant temperature), the fuel rack is moved into Start position (max. 19.5 mm travel), direction "A", by the IFI fuel metering control (Y23/1).
The fixed-value coil (b) is actuated by the IFI control module (N3/7) with a frequency of 10 kHz and a pulsating D.C. voltage (about 1.5 V). The short-circuit ring (e) of the fuel rack (2t) moves away from measuring coil (d). As a result, the magnetic field (inductance) of the measuring coil (d) is built up to a maximum (2.8 V). The voltage drop of the measuring coil (d) is thus at its minimum.







Closed throttle position, blipping throttle
Amplitude modulation

Inertia fuel shutoff
During inertia fuel shutoff (zero delivery, 0 mm travel), the short-circuit ring (e) of the fuel rack (2t) moves toward the measuring coil (d) in direction "B". As a result, the magnetic field is reduced (1.6 V). The voltage drop through the measuring coil (d) is thus at its maximum.

Driving
When driving, the short-circuit ring (e) of the fuel rack moves between the minimum and maximum range in line with the accelerator pedal position.
The frequency of 10 kHz remains unchanged in all operating states.







Control travel after 30 s, ignition "ON"