Are there 2 crank sensors or 1 on the m30 3.5L?

[Felixdacat]

I am going to replace my crank sensor, and I have found a couple of sites saying I need 2. One in the front of engine, and one on the back of the engine. I also found sites saying only one. Which one is it?
Thanks in advance.......Felix So far found one for $93.00 ea shipped

[winfred]

e34/e32 has one sensor on the front, e28/23 has two sensors on the tranny, some two sensor cars have another for the diagnostic plug on the front

[Felixdacat]

Thanks for clearing this up for me Winfred.