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Crankshaft position sensor

Crankshaft position sensor





The engine control module receives information on the engine speed and when the engine is at top dead centre from the crankshaft position sensor. This information is used to calculate the permitted injection quantity and to determine when fuel pressure build-up should start.

In one of the crankshaft balance weights there are four air gaps that induce an alternating current when they pass the sensor. The frequency of this current is proportional to the engine speed. Two of the air gaps are used by the control module to mark top dead centre. These air gaps are displaced 13° in relation to top dead centre.

Note that the special tool for locking the engine at top dead centre does not fit the crankshaft position sensor air gap. Instead, there is a special recess for the tool that is not displaced in relation to top dead centre.



Diagnosis

The following diagnostic trouble codes are generated if a fault should occur in the crankshaft position sensor:


• P0335 Tachometer sensor, No Signal While Motor Running

• P0336 Tachometer sensor crankshaft, Plausibility fault with pump camshaft sensor.

• P0337 Tachometer sensor, No Signal During Start Procedure


Pump rpm x 2 is used as a substitute value for the crankshaft position sensor.