I am wondering if there is a way of testing the speed and reference sensors on my 951? The car won't start. I have replaced the DME relay. I changed both computers and still nothing. I thought that the tach was bouncing but if it is, it is very very slightly and only when you initially hit the key. I got the front sensor out and wondered how to check it...anyone?

 

You really need to check the sensors with an oscilliscope, but clarks-garage has a procedure with a multimeter.

www.clarks-garage.com go to his garage shop manual, and under 's' pick speed and reference sensor testing.

If that doesn't get you anywhere, I can post the pages out of the shop manual.

 

Just checked them both...seem to be getting a high reading on the reference sensor. I think i will order both in to be safe. Thanks for the help Doc!