Cranks shaft position sensor wiring schematic/ohm readings - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Jojo · 01-02-2017, 03:58 AM

Hi,

I'm trying to configure whether I have a faulty CPS.

Maybe someone can tell me what ohm meter readings I should read and also the pin numbers of the sensor?

Thanks,

Anker · 01-02-2017, 06:01 AM

JoJo,

I don't believe it is that simple. If it is a hall effect sensor (which I suspect) you can't do meaningful static readings. If I get a chance I will look up in the repair manual for diagnostic tests. I have a nagging suspicion the best test is to replace it and see if the problem goes away.

JFP in PA · 01-02-2017, 06:55 AM

Quote:

Originally Posted by Anker

JoJo,

I don't believe it is that simple. If it is a hall effect sensor (which I suspect) you can't do meaningful static readings. If I get a chance I will look up in the repair manual for diagnostic tests. I have a nagging suspicion the best test is to replace it and see if the problem goes away.

Remove the CPS sensor connector, connect your multimeter to pin #1 and pin#2, at 68F it should read 0.8-1.0K ohms; then connect the multimeter to pin #1 and pin #3 and it should read infinite ohms; if it does not read correctly in either range, can the sensor and replace it.

Anker · 01-02-2017, 06:11 AM

I just checked and I am correct, the sensor is a hall effect sensor. I did not find any specific diagnostics for it.

I did not read all the previous posts on this issue, but have you checked the codes? I would be very surprised if there isn't a code for a failed cam position sensor. You will need a code reader that can read the manufacturer specific codes.

For the sensor I would expect two pins. Try to measure the resistance between the pins. If it is zero it is definitely defective. It could also be something as simple as a badly seated plug.

Anker · 01-02-2017, 06:22 AM

The cam position sensor is on the right side of the engine all the way towards the rear on the cylinder head.

Anker · 01-02-2017, 06:34 AM

Bummer, I was looking at cam shaft position sensor, but you were asking for crank shaft position sensor.

The crank shaft position sensor is also a pulse sending unit and works off the flywheel. Everything I said about the camshaft position sensor also applies here. The sensor itself is mounted on the crank case.

Jojo · 01-02-2017, 07:13 AM

Yes I have a ScangaugeII which shows me P0335. Funnily enough, the car started with the CPS disconnected, however it did take some extra cranking, but did not wait till the engine is warmed up to see what the effects are, if any

I think I shall place an order for a new one and see how it goes and will let you know....

Cheers
JJ

911monty · 01-02-2017, 10:04 AM

Quote:

Originally Posted by Jojo

Funnily enough, the car started with the CPS disconnected, however it did take some extra cranking, but did not wait till the engine is warmed up to see what the effects are, if any

I think I shall place an order for a new one and see how it goes and will let you know....

Cheers
JJ

You might double check that it was the CPS you disconnected. The CPS is the trigger that tells the DME where the pistons are in relation to TDC in order to fire the spark plug coils. Without it connected the engine will not run.

particlewave · 01-02-2017, 08:57 AM

Taking a resistance reading on a sensor like this will tell you exactly squat.

Remove the fuel pump relay (so the engine won't start) and turn the key. Does the tach needle bounce when you crank the engine? If it does, the CPS is fine. If the needle doesn't move at all, it's likely bad.