Crankshaft Position (Cp) Sensor
To provide EEC system with accurate timing reference, the rear of the crankshaft is fitted with a 4-lobe pulse ring. See Fig 1. The ring is positioned 10 degrees in advance of TDC, to set basic engine timing at 10°BTDC. The crankshaft position sensor is fitted on rear, right side of engine block. See Figure.
As crankshaft rotates, the lobes of the pulse ring pass the crankshaft position sensor. The sensor's magnetic field is interrupted and an output voltage pulse is generated and sent to the ECA.
The ECA uses these pulses to determine crankshaft position for ignition timing. Since the crankshaft position sensor tells the ECA when to fire the ignition module, a defective sensor or sensor wiring can prevent the vehicle from starting.