Cam position sensor code p0344

[Derick Tremblay]

2003 Porsche cayenne s  getting code p0344 , scanned with durametrics and inspected readings of position sensors  on both cams, note I have +or - 8 on bank 2 ( with in spec ) and I don't even have a reading on bank one... suspected that I have a dead sensor .. tested by swapping both sensors problem still persists, inspected wiring from ecm to sensor all ok 0.4 ohms resistance .. all within spec.. inspected pick up  on cam position sensor on intake cam , compared with bank 2 ,, measured height and gap of pick up ring.. both are same .... inspected basic engine timing  both plates that lock cam shaft are lined up and pin at crank is in place,  now im left with no other ideas ,,,NOTE I suspected I had a faulty ecm I decided to swap signal wire from position sensor 1 and 2  at ecm  problem jumped to bank 2 ,,, by doing this we know that the ecm is reading correctly ... ive been a VW dealer tech for the last 9 year and this is the first time that ive been stumped on a vehicle,,, just wondering if anyone has seen this type of issue or can shoot me in to a direction thx in advance!!!

[Loren]

If that is the only fault you have then the diagnostica manual clearly states:

 

Possible cause of fault:

- Camshaft rotor (phase sender wheel) damaged

[Ahsai]

If you use an oscilloscope to probe both cam sensors and compare their waveforms, that should reveal something.

[Ahsai]

A video of how the waveform should look like 

[Derick Tremblay]

I do do not have an scope at the shop ... if i did this would have been the first things i would have done, very expensive for the amount of times im going to use it , and ive seen this video thx ahsai appreciate the link.   ive measured and inspected my sender  and i assure u that it is not damaged ... i could understand if one of the ears are bent in or are completely damaged but there is  nothing to say otherwise .. and for me to throw a 1200$ intake cam at it it seems a little steep, 

[Ahsai]

I think the danger of $1200 intake cam is it may not solve the problem (if something else is the culprit). Without a scope, it's difficult to pinpoint the problem given what you have already tried. If the bank 1 cam sensor is bad, you would expect swapping the sensor will fix bank 1 but it didn't. I think this case is interesting given what you tried so far, nothing can conclude it's the sensor or the reluctor. Perhaps try a new sensor on bank 1. I don't know if visual inspection of the sender and resistance are enough to OK it for it can also act up (signal drop) only when hot?

 

http://www.amazon.com/Bosch-0232103022-Engine-Rpm-Sensor/dp/B0074O6XFG

 

 

BTW, I use this $150 scope and it's excellent for problems like this http://www.sainsmart.com/dso203-mini-kit-72mhz-4-ch-stm32-metal-shell-newest-version.html?gclid=CJLCqOfm18oCFRCqaQodEN0Grw

Edited February 2, 2016 by Ahsai

[Derick Tremblay]

yes i will inspect this scope thx .   what im not getting is a reading from my cam sensor bank 1 with my durametrics i don't believe its the sensor because when i swap it the problem is still present on  bank 1, it should be straight forward ,, ecm good ... wiring good,,, sensor good,,, now im questioning my measurements on that sender ring , this is a pressed on ring ,, wondering if it could spin on the cam and can just be out of spec to the point that it cannot be red by my durametrics? wondering if any one has any specs on that sender for me to measure to make sure it is facing the correct way?

[Ahsai]

I don't have the answer but from the video above, it seems to imply the two signals should be on top of each other? If true, that means the reluctor ears' positions (with respect to the sensors) should also be identical between the banks. I could be totally wrong though.

Edited February 2, 2016 by Ahsai

[Derick Tremblay]

I don't have the answer but from the video above, it seems to imply the two signals should be on top of each other? If true, that means the reluctor ears' positions (with respect to the sensors) should also be identical between the banks. I could be totally wrong though.

yes i do agree with that video . if they are not matching or lined up then it would seen like i have a timing issue or an issue with my cam adjuster.  ive just ordered a dso from snap-on yesterday . should be coming in this week. 

[Ahsai]

"dso from snap-on" = $$$$$$ :)

[Derick Tremblay]

yes it was .. now I pined both cam position sensors and inspected both readings to see if they match up , and they do ..  Im not sure how to add a picture on this forum so im not able to upload one at this time but they line up .. witch to me makes absolutely no sense, if they dso is able to pick up a reading why cant my cam sensor??? now again I decided to swap sensor same result .. I could understand if my cam way out of time ,, but it isn't and I should be able to get some sort of reading. now I performed and overlay on the 3 cam wires still with same result .. I know the fault code says that there is a damage pickup ring but if I did they would not line up so well on the dso and the reading would be all out of wake... how do I add a picture ?

[Ahsai]

Wow, that's strange. I was expecting misaligned signal or malformed signal.

 

I assume you tested everything at idle? Is it possible the timing issue will show up at higher rev (or when driving) when the variocam kicks in? Maybe to hook up the scope inside the car and go for a test drive? Just a thought. Otherwise I agree this is very strange since the DSO shows the correct and lined up signal. If the DSO can pick it up, the ECU should also be able to pick it up and also you've checked the wire between the ECU and the two sensors already.

 

To add pics, click on the "More Reply Options" button then on the bottom left there should be an "Attach this file" button. Perhaps because you only have 5 posts so far so that's disabled for you.

[Ahsai]

Perhaps try to duplicate freeze frame conditions?

[Derick Tremblay]

I ran an overlay to the ecm with my test leads,  sensor to ecm .  and yes it has only been tested at idle , but I find it strange that I cant even see anything with my durametrics on bank one .  but as soon as I swap bank one and bank 2 pins in the ecm im able to pic up bank one on the screen but its actually seeing my bank 2.  here is the picture  let me know what u think.  

[Derick Tremblay]

Green is my bank1 the one im not picking up with the scanner and yellow is 2 , tm morning i think im going to compare my crank and cams will see what i get from that.

[Ahsai]

Can you increase the time divison (zoom out) to show a complete period of both signal? Currently it's showing a partial period. Maybe the problem is at the rest of the signal pattern. Also, can you try back probing the ECU side pins to make sure the DSO measues what the ECU sees on its pins?

Edited February 5, 2016 by Ahsai

[Derick Tremblay]

yeah i pined it directly at the ecu , pin 86  and 87, how far off does the signal need to be for it to be lost and not picked up by the ecm ?? i think im about to pull both cam and compare them side to side and make sure that the pickup rings are exactly the same.

[Ahsai]

No, the signal should not attenuate that much. I was juat worried about broken/shorted wires. I know you checked before though.

The signal is so clean and sharp so theres real no good explanation of the reluctor being damaged. Still want to see the whole pattern of the signal though.

[lewisweller]

On 05/02/2016 at 8:49 PM, Derick Tremblay said:

yeah i pined it directly at the ecu , pin 86  and 87, how far off does the signal need to be for it to be lost and not picked up by the ecm ?? i think im about to pull both cam and compare them side to side and make sure that the pickup rings are exactly the same.

Derrick did you get this fixed? Pls detail the findings and also explain briefly the symptoms of running with this error. Thank you.