ABSTRACT
The issues and diagnostic techniques used for sensors and actuators are common to many systems. For example, the testing procedure for an inductive engine speed sensor on a fuel injection is the same as for an inductive speed sensor on an antilock brake system (ABS). Testing sensors to diagnose faults is usually a matter of measuring their output signal. In some cases, the sensor will produce this on its own (e.g. an inductive sensor). In other cases, it will be necessary to supply the correct voltage to the device to make it work (e.g. Hall sensor). It is normal to check that the vehicle circuit is supplying the voltage before proceeding to test the sensor.
