How Camshaft Position Sensors Works

[Carl Fredrik Ahl]

Hi,

I know that camshaft position sensors works by reading when there are blank spots in the camshaft. I wonder HOW it reads that. Is it magnetic?

[StringJunky]

6 hours ago, Carl Fredrik Ahl said:

Hi,

I know that camshaft position sensors works by reading when there are blank spots in the camshaft. I wonder HOW it reads that. Is it magnetic?

Yes, it detects the magnetic variation as the camshaft rotates. It exploits the Hall Effect.

Quote

The task of the camshaft sensor is to work with the crankshaft sensor to define the exact position of the crankshaft drive. Through the combination of both sensor signals, the engine control unit knows when the first cylinder is in the top dead point.

This information is needed for three purposes:

For the start of injection during sequential injection.
For the actuation signal of the solenoid valve for the pump-nozzle injection system.
For cylinder-selective knocking control.

The camshaft sensor works according to the Hall principle. It scans a ring gear on the camshaft. The rotation of the ring gear changes the Hall voltage of the Hall IC in the sensor head. This change in voltage is transmitted to the control unit and evaluated there in order to establish the required data.

https://www.hella.com/techworld/uk/Technical/Sensors-and-actuators/Camshaft-position-sensor-3899/

 

[Carl Fredrik Ahl]

7 hours ago, StringJunky said:

Yes, it detects the magnetic variation as the camshaft rotates. It exploits the Hall Effect.

Ok, so both the camshaft and a piece of the camshaft sensor is magnetic and when there is a blank spot, the magnetic force between the camshaft and the camshaft sensor decreases and the sensor sends that to the car computer so it will know the position of the camshaft?