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Crankshaft Sensor Inductive (Engine Cranking)

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Crankshaft Sensor Inductive (Engine Cranking) Waveform Notes

In this particular waveform we can evaluate the output voltage from the Crank Angle Sensor (CAS). The voltage will differ between manufacturers, proximity and engine speed. The main reason for evaluating this waveform is to monitor the output when the engine fails to start due to a loss of primary triggering. The waveform will be an Alternating Current (AC) its voltage will be low when cranking and seen to increase with engine speed. The gap in the picture is due to the ‘missing tooth’ in the flywheel or reluctor and is used as a reference for the ECM to ascertain the engines position. Some systems use two reference points per revolution. The minimum voltage requirement is crucial as while a small AC voltage may be present, it may be insufficient to trigger the primary circuit