Ignition Hall Effect Sensor: Description and Operation

Hall Effect Distributor:

The engine controller receives input on engine speed from the distributor pick-up. The distributor uses a Hall effect switch to create a digital signal that is sent to the engine controller.

The distributor has a Hall effect switch and a shutter that are used to generate signals that are sent to the engine controller. The shutter contains six blades, one for each cylinder. The Hall effect switch is located on the switch plate of the distributor, and has a magnet mounted a specific distance from it. The shutter passes between the Hall effect switch and the magnet, interrupting the magnetic field. When the magnetic field is interrupted the Hall effect switch senses the change and turns the switch OFF until the magnetic field is sensed by the magnet (then the switch is turned ON). The turning ON and OFF of the Hall effect switch causes pulses of voltage to be generated. These pulses of voltage are the input signals that are sent to the engine controller. The engine controller calculates engine speed from these pulses, based on the number of pulses that are generated.

If the SBEC does not see any input from the Hall effect pick-up, then the ASD relay will not be activated by the SBEC. If the ASD relay is not activated by the SBEC, then no power will flow to the fuel pump, fuel injectors, or ignition coil thus preventing fuel injection. If this situation occurs, a no start condition will exist.