Functional description

The intake camshaft sensor enables the engine control system to detect whether the 1st cylinder is in the compression phase or charge cycle phase. In addition, this sensor delivers the feedback signal for camshaft position which controls the variable camshaft timing control (VANOS).

The intake camshaft sensor is designed as an inductive hall effect sensor. The camshaft sensor wheel has 6 different flank spacings. The flank spacings are detected by the hall effect sensor.

The engine control system uses these to calculate: here

• Camshaft speed
• Camshaft speed
• Exact position of the camshaft

Fig 1: Identifying Cylinder Head Cover

Courtesy of BMW OF NORTH AMERICA, INC.

This graphic shows the N63 engine (contents of brief component description apply in principle to other engines as well).

For starting the engine, the engine control unit checks the following preconditions:

• Error-free signal from the crankshaft sensor
• both signals must be detected in a specific chronological sequence

This process is referred to as synchronization and is only performed when the engine is started. It is only the synchronization process that enables the engine control unit to activate fuel injection correctly. The engine will not start without synchronization. When voltage is applied, it is detected whether the sensor is above a tooth or above a gap.