Speed sensors rear

Hi 

Anyone know the resistance readings that a working oem speed sensor should give?

I ve a very intermittent fault, can be fine all day and then randomly re occur (all the ESC/ABS/parking assist warning/stop start lights) that a borrowed obd2 scanner does not show up, one sensor is 6.5Mohms and the other 2.4Mohms, a new but different brand is 0.5Mohms.

I don't want to use it as i wont be able to send it back if the issue is somewhere else, don't know anyone with a different scanner other than dealers and i'm on a budget!!

15k miles ago, when it was my company car, a garage supposedly change the NS rear sensor but i think they didn't as its identical to the OS and equally dirty rusty etc, though i guess they could have swapped for a 2nd hand one.

Aside do only some OBD2 readers work with Skoda's ?

Thanks.