Camshaft Hall Sensor, Basic Function - GF15.10-P-2001A

Engine all (CAR) 

Overview 

This document contains information on:

• General 
• Location 
• Function 

General 

The Hall sensors detect the camshaft positions without making contact for the following functions:

• Camshaft adjustment
• Synchronization of ignition and injection sequence
• Recognition of ignition TDC (top dead center)
• Emergency engine start in case of defective crankshaft Hall sensor

Location 

The Hall sensors are located on the cylinder head above the respective camshaft.

Function 

The inserts on the pulse wheels of the camshaft, which are made of ferromagnetic material, change the magnetic field in the Hall sensor when they pass through the Hall sensor and therefore change the field strength of the voltage of the semiconductor element. The resulting sine-wave voltage is converted into a square wave signal and increased. The magnetic field of the permanent magnet constantly applies a magnetic bias voltage to the semiconductor element.

Detection of the camshaft takes place via the position of the camshaft pulse wheels. Via the evaluation of the Hall sensors, the individual cylinders can be assigned to the respective working cycle.