Camshaft Position Sensor issue, 08 VW Passat 2.0 TDI BRM

Hi All,

I am look at an issue with a Camshaft Position Sensor DTC i get "Sort to Plus" I am doing some trouble shooting on the wiring and looking for some pointers, here is what i have found

Unplug the sensor and probe the connector, i get 5v on pins 2 and 3, now when i prob the ECM side i get 5v and 12v, i can't find anywhere that tells me the actual voltage i should be getting at the ECM, that my first question can anyone find out what voltage i should be getting at the ECM?

I am probing pin A27 i get 5v pin A28 i get 12v

Now i'm only getting 5v when i probe the connector also when i test for continuity on that wire it is open, so i am sure there is a problem with the wire, my 2nd question is, if there was a short could that fry the ECM? the 12v from A28 seems high to me but to tell you the truth i'm still learning alot

Pin A28 is signal input to ECM and must have 5volts or 0volts depends if it is pull up or pull down, A27 is signal output 5volts and A12 is 0volts. 12 volts is not good!

Yeah i was thinking that, if there is a short to positive that would cause the 12v at the ECM so if i cut the signal wire and then probe the ECM i should see 5 or 0v? if i see 12v at this point do you think i have a bad ECM?

Yes, but you need to check ECM plug it can be shorted inside! Check ohms against the other pins around.

So i was probing the wrong PIN !!! new specs i need.

so voltages were all good, i removed the crank sensor and the car started so i am sure its a timing issue, as i was getting both crank and camshaft on my scope

But anyway, the car was belting out white smoke, done a head gasket tester and it looks like its a head gasket, so i will get the head off and get it swapped, and also setup the timing correctly, I will let you know how i go

Ok so an update, i replaced the head gasket and the injector seals, and the timing is now perfect i bough the correct tools!, but the car still wont start with the crankshaft sensor connected, i am getting a signal when i put the scope on to it, has anyone came across this before?

When i remove the crank sensor it has a long crank but does start and run a little rough on idle

Here is my cam crank on the scope, i dont have a know good one so cant say that this is good or not

It does not look a very nice signal, there should only be square waves!

Hi Guys, just an update in case anyone has the same issue

It turned out to be the sender ring on the crankshaft that the crankshaft sensor reads had moved about 20deg although the timing was good, the cam and crank could not correlate the signals so the engine would not fire and removing the crank sensor the car would fire up, ran rough but would start, any way had to get the gearbox out and move the ring with some gentle persuasion lol

Thanks for you input