2.5tdi AKE idle at 910 but 725 on computer.

[Stereoflaver]

What reads the engine speed, is it the crank sensor and why would it be wrong ?

What else would it affect as the ecu thinks it's 185rpm lower.

[ametlib]

Hi,
good question !
The ECU reads the rpm from the crank sensor wich sends 6 signals per revolution( there are 6 pins in the flywheel)
My first thought was there was 1 pin missing ? but the mathematics are wrong, should have been 758 rpm then, and the engine would probably run like s#%t.
How do you know the real rpm are 910 ?
And why 725 and not 742 ?