Manifold absolute pressure sensors measure changes in intake manifold pressure caused by changes in engine speed and load, and convert them into electrical signals.
The air vortex sensor uses whirlpools of air, produced by a vortex-generating rod, to measure the volume of air entering the engine. This is converted to an electrical signal that is transmitted to the ECU.
The fuel system sensor determines how much fuel the engine needs at that instant, then grounds the injection valve circuit, to open the solenoid-operated injectors. This information is relayed as electrical signals to the ECU.
Exhaust gas oxygen sensors monitor the oxygen content of the exhaust gas, and relay this information, by means of a voltage signal, to the control unit.
Crankshaft position and speed can be detected by inductive-type sensors which act as small alternators. The frequency of the pulse they transmit allows the ECU to detect engine speed.
A Hall effect sensor provides voltage pulses that are generated by alternately shielding the sensor from a magnetic field, then exposing it. An ECU uses this signal to detect engine speed and control ignition timing.
