Crankshaft Position Sensor
The Crankshaft Position (CKP) sensor is located on the left side of the crankshaft rear oil seal housing. The sensor lead passes through a cover in the side of the cylinder block. The sensor tip is aligned with a reluctor ring on the transmission drive plate. The sensor produces a square wave signal, the frequency of which is proportional to engine speed.
The Powertrain Control Module (PCM) monitors the CKP sensor signal and can detect engine over-speed. The PCM counteracts engine over-speed by gradually fading out speed synchronized functions. The CKP is a Hall effect sensor. The sensor measures the magnetic field variation induced by the reluctor ring.
The reluctor ring has a 60 minus two pole pattern. The missing poles provide a reference point for the angular position of the crankshaft. When the space with the two missing poles passes the sensor tip, a gap in the signal is produced which the PCM uses to determine the crankshaft position.
The PCM uses the signal from the CKP sensor for the following functions:
- Synchronization
- Determine fuel injection timing
- Produce an engine speed signal which is broadcast on the FlexRay bus for use by other systems.
The CKP sensor receives a 5V supply from the PCM. Two further connections to the PCM provide ground and signal output.