Bosch Crank/Flywheel sensor

[MikeS911]

Hi All. Can anyone confirm if the Bosch Crank/Flywheel sensor for the 964 is a VR sensor or a Hall sensor. Thanks Mike

[fetuhoe]

I thought they were inductive.

[smallspeed]

They are inductive - which makes them VR I think in ECU terms

[MikeS911]

Thanks guys, thought they were VR but they have three terminals, so wanted to check. I guess they are + - and shield.

[smallspeed]

3 pins will probably be Signal +, Signal - and shield ground if its a VR sensor. VR sensors produce a weak induced sine wave signal (usually millivolts range, but the output increases with speed). Because of this they're very susceptible to noise so need shielding. Usually the shield is just grounded at one end I think?

Hall sensors are powered and produce a signal in the "volts range" so less susceptible to noise - they're usually +12v, GND and Signal Out. The other advantage is they produce a square wave so don't require ECU power to process!