| Fig. 1: Camshaft position sensor at the side of the camshaft
support — Impreza
|
The CMP sensor located on the side camshaft support, or in the distributor, detects the number of pulses which occur when protrusions at the back of the camshaft drive sprocket cross the sensor.
The reference signal detected by the photoelectric CMP sensor are sent to the ECU. The ECU determines the optimum ignition timing from these signals and other engine operating parameters and transmits an ignition signal to the ignition coil igniter. The igniter amplifies the ignition signal and causes the primary current to flow intermittently in the ignition coil.
