Operation CHARM: Car repair manuals for everyone.

Ignition Hall Effect Sensor: Description and Operation

Hall Effect Distributor:





Hall Effect Pickup Assembly:





Location

Sensor (pick-up), mounted on distributor plate.

Purpose

The Control Module uses sensor input to determine engine speed and cylinder identification, and synchronizes fuel injection accordingly.

Operation

Pick-up generates pulses when shutter blades interrupt magnetic field in pick-up.

Theory

Hall effect switch is mounted opposite a magnet.

A shutter wheel, containing four shutters, (one for each cylinder), passes between Hall Effect switch and magnet.

- When a shutter interrupts the magnetic field, the switch turns OFF (0 volts).
- When a window passes through the magnetic field the switch is turned ON (approximately 5.0 volts).

Turning the switch ON and OFF generates voltage pulses which are sensed by the PCM.

NOTE: If the PCM does not sense input from the Hall Effect pick-up, PCM will deactivate Auto Shutdown ASD and fuel pump relays. This interrupts voltage to the fuel pump, fuel injectors, and ignition coil, (a no start condition).