10.15 - Crank Sensor ( ,  )

The crankshaft speed/position sensor located at about 10 o’clock on the front pulley.

It is attached with an Allen screw so that face is a few mil from toothed wheel that sits immediately behind pulley. The action of the Iron toothed wheel and the coil & magnet of sensor produces electrical pulses to ECU.

From this the ECU knows how fast engine is running. You will also notice that wheel has a missing tooth. This gives a long pulse to ECU so it can work out where crankshaft is and so get ignition and injector timing correct (It counts the teeth from the gap)

The sensor is a little bit tricky to remove because of its position. There is a barrel connector at the front of the cylinder head which should be held in place with a tie wrap. Another tie wrap is often put on cable down to sensor. It might be easier if you move a hose clip or two out of the way.

Clean connector first - it could be a corrosion issue (front of engine is not a great place to live). With the Allen bolt removed the sensor can be pulled out of bracket (there is only the one bolt).

The sensor has 3 wires two carry the signal from coil and should be about 1400 Ohms. The third is a screen which goes nowhere.

Crankshaft positioner Testing :

The CPS can be measured (with multimeter) for volts (AC Mode) are 2.5 VAC at 1000 RPM and 5.0 VAC at 3000 RPM. The resistance in the CPS coil should be between 1.25K and 1.45K ohms. An open circuit would indicate a failed sensor. An oscilloscope is actually needed to read the pulses during cranking.

Check the CPS for correct position. The gap between the crank sensor core and the toothed wheel should be 0.020-0.040 in.