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Cranskshaft position sensor woes

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Hi all,


First thread on here, and one which I hope helps others. 


2006 E60 523i here. I've been through the ringer recently with random gearbox behaviour: violent gear changes, sometimes with a "transmission fault" message, sometimes with the engine cutting out. Long cranks at startup was another random aspect of this.


Luckily I have INPA and having read the codes after many such incidents I was reasonably confident that I had a crankshaft position sensor problem. The recurring codes were 51a7 and 2a94. There are cheap aftermarket parts available but with so many unfortunate stories out there I decided to purchase an OEM part from the stealership (EUR 160).


Left the car with my local mechanic to replace. The garage called to tell me it wasn't a CPS problem at all, but rather the connector into the CPS. It was perished and broken. Back to the stealership, and they told me that the cable was part of a larger engine wiring harness, that it was all one sealed unit....and the cost for a replacement? EUR 700+!!! Now, bearing in mind that the car is probably only worth a couple of grand, I was fearing for the future of my car!


Thankfully, this wonderful page came to the rescue:



Long story short, the connector can be rebuilt. BMW parts below:

1 X Socket housing (12527507526)

3 X Grommets (61138366245)

3 X Terminal pins (12527545852)


Total cost from stealership: EUR 6.70.


One final note - 

There are lots of DIYs and videos out there of folks replacing the CPS from above. This generally involves removing the intake manifold for access - major PITA!! My mechanic was able to do the whole job from below. See this vid for reference:







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