Camshaft Position (CMP) Sensor (Q45)

CMP sensor monitors engine speed and No. 1 cylinder TDC position. This sensors primary function is to provide the PCM with No. 1 cylinder TDC signal during start up. PCM uses this signal to determine the proper firing of each ignition coil. CMP sensor has outer slits (1°) and inner slits (45°) on a disc. An LED light and photo-diode, for each set of slits, creates a pulsating voltage when LED light is broken. The outer ring is for engine speed and the inner ring determines No. 1 cylinder TDC position for injector and ignition timing.