Other important tests are measuring the fuel pressure, in order to identify other components that may be faulty (fuel pump, fuel filter, pressure regulator), and checking the intake and exhaust systems for leaks, to prevent false measurement results. If the sensor has a 2-pin connector, it is most likely to be an inductive sensor. In this case, the internal resistance, a potential short circuit to frame, and the signal can be determined.
To do this, remove the plug connection and check the internal resistance of the sensor. If the internal resistance value is 200 to 1,000 ohms (depending on the reference value), the sensor is OK. If the value is 0 ohms, there is a short circuit, and in the case of M Ohm there is a break. The test for a short circuit to frame is carried out using the ohmmeter from a connection pin to vehicle ground. The resistance value must tend toward infinity. The test using an oscilloscope must result in a sinus signal of sufficient strength. In the case of a Hall generator, only the signal voltage in the form of a square wave signal and the supply voltage are to be tested. This must result in a square wave signal depending on the engine speed. We should repeat at this point that the use of an ohmmeter can destroy the Hall generator.
