2003 Boxster Stalls When Warm Already Changed CKP

[vosko]

I purchased this car with this problem from the second owner with 120k miles. If you let the car idle up to operating temp it will stall, then it will not restart without giving throttle. Eventually won't start or idle at all. and I will get a CEL and P0335 CKP code. Randomly i received a P0012 code for camshaft position timing over-retarded bank 1 once. I read up about the CKP issues and ordered a new Bosch sensor and installed it. Same problems, popped open the DME, looks brand new inside. Previous owner had a damaged immobilizer repaired due to water damage. I decided to try my luck and take it for a 1 mile ride. It stalled, got it going again, another stall, going again. Finally parked it at my destination, came out two hours later. Crank and no start, and tach is dead. If i leave the key in the on position, i can hear a relay blip on for a second then the tach will jump up to 5k rpm every few seconds, without cranking. I swapped the relays side to side same issue, except the top two which are different. There is currently no CEL on. I am not afraid to dig into this thing but the only diagnostic tool i have access to is a generic Autel OBD2 scanner. I searched and everyone says CKP sensor..... seems like there was nothing wrong with the old one. Could it be a DME problem ? 

Edited July 8, 2016 by vosko

[JFP in PA]

I purchased this car with this problem from the second owner with 120k miles. If you let the car idle up to operating temp it will stall, then it will not restart without giving throttle. Eventually won't start or idle at all. and I will get a CEL and P0335 CKP code. Randomly i received a P0012 code for camshaft position timing over-retarded bank 1 once. I read up about the CKP issues and ordered a new Bosch sensor and installed it. Same problems, popped open the DME, looks brand new inside. Previous owner had a damaged immobilizer repaired due to water damage. I decided to try my luck and take it for a 1 mile ride. It stalled, got it going again, another stall, going again. Finally parked it at my destination, came out two hours later. Crank and no start, and tach is dead. If i leave the key in the on position, i can hear a relay blip on for a second then the tach will jump up to 5k rpm every few seconds, without cranking. I swapped the relays side to side same issue, except the top two which are different. There is currently no CEL on. I am not afraid to dig into this thing but the only diagnostic tool i have access to is a generic Autel OBD2 scanner. I searched and everyone says CKP sensor..... seems like there was nothing wrong with the old one. Could it be a DME problem ? 

 

Welcome to RennTech :welcome:

 

Yes, it could be a DME issue, but a proper scan should pick that up.  The codes you have already gotten indicate no signal from the CPS (P0335) and the inability to get a comparison between the cam position sensor on bank #1 and the CPS (P0012), which would seem probable if the CPS were bad, but you have already replaced that.  What concerns me is the jumping tack, which is very abnormal.  I would get the car scanned with a Porsche specific diagnostic tool for pending codes as the first step.

[vosko]

I am using a basic Autel AL519 scanner, did a little searching and found a video of a gentlemen diagnosing his 911 with an Autel Maxidiag Elite MD802. I think it might be time to upgrade. The MD802 showed dme/abs/alarm codes/faults etc in addition to regular OBD2 codes. I have multiple makes of cars, so it does not make a lot of sense to buy something that only works on this vehicle. The Maxidiag looks like it should do the trick? Video link below.

 

[JFP in PA]

While the Autel MD802 is a fine global OBD II tool, it still lacks much of the ability of the Durametric system.

[vosko]

A friend has a Durametric but he is 90 minutes away. Let me see what i can do. Thanks for the suggestions!

[Ahsai]

Sounds like you have problems with your wires between the DME and the crank position sensor. I just helped another gentleman with the same problem here:

 

http://rennlist.com/forums/996-forum/935933-replaced-aos-now-cps-is-bad-no-start-3.html

 

Post #31 has the diagnostic steps for a 996 so you need to find the right wiring diagrams for your car. The diagnostic principles are the same though.

[vosko]

So the car sat overnight, started right up today and it drove a mile back home. Sure seems temperature related to me. The problem i have is similar but not identical. It sure looks like it will be really fun to try and trace the CPS wiring....My friend just happens to be in town Monday morning, so we are going to hook up his Durametric and see what comes up. 

[Ahsai]

BTW, unrelated to the CPS DTC but it's a good idea to clean the throttle body and idle stabilizer if your engine stalls when idling. You can activate the idle stabilizer with a 9v battery to make it turn so you can clean it more thoroughly.

[vosko]

I borrowed a Durametric, cleared the codes then drove it around. The DME was attached to the firewall and seemed VERY hot. I have it loose at the moment but the car is still acting wonky. These are the current DME codes....

Edited July 18, 2016 by vosko

[Ahsai]

Looks like your bank 1 cam sensor/circuit is also bad. I don't have the wiring diagram of your car but the cam sensor should have 3 pins - 5v, ground, and signal. You can unplug the sensor and wIth key ON engine OFF, the 5v pin should get 5v.

Edited July 19, 2016 by Ahsai

[vosko]

I will order up a camshaft position sensor.... Any idea on those other codes ? 

[Ahsai]

You still have the crank position sensor code despite a new sensor so I think you need to check the wiring between the sensor and the DME.

 

The other misfire codes are probably due to the crank and cam sensor issues but they are only on bank 2 so that may indicate something bank 2 specific. Anyway, you will need to address thise sensor codes first before the misfires.

[vosko]

I meant the other three codes in the AC.ABS, and cluster. Makes me think the DME is bad. I did inspect it and could not find anything obviously burnt or bad cold solder joints. The car will run fine cold, warm up then start missing and stall. You can get it started again if you give it throttle, then you have a 50% chance of it being driveable.... It will not give those codes or CEL until warmed up, Also it won't even CEL or give those codes until it stalls a few times. 

[Ahsai]

Possible since you said it's very hot. I've never used them but seems like they can diagnose your DME for $75. Sounds reasonable to me.

http://www.ecudoctors.com/ecu-fault.html

[Ahsai]

The a/c, ABS, instrument codes seem to point to the CAN bus.

 

I hope John will chime in soon.

[vosko]

Yeah, I ordered the camshaft sensor. I am just hoping to not swap more parts and find out it was a DME issue to begin with. I tested the original crankshaft sensor and it ohm'd out correctly. I figured since other people have had them fail its worth it to just have a new one in there anyway. I am chasing my tail a bit with this so far

[JFP in PA]

2 hours ago, Ahsai said:

The a/c, ABS, instrument codes seem to point to the CAN bus.

 

I hope John will chime in soon.

Are you getting these codes while testing the car while it is not running?  Reason I ask is that you are possibly are getting the CAN Bus codes because the system is timing out and going to sleep on you.  Try clearing all of the codes, running the car, and then rechecking them, but this time if you turn the car off, leave the four way flashers on, which will keep the car from timing out and going to sleep on you. 

[vosko]

On 7/19/2016 at 3:51 PM, JFP in PA said:

Are you getting these codes while testing the car while it is not running?  Reason I ask is that you are possibly are getting the CAN Bus codes because the system is timing out and going to sleep on you.  Try clearing all of the codes, running the car, and then rechecking them, but this time if you turn the car off, leave the four way flashers on, which will keep the car from timing out and going to sleep on you. 

Yes, But what one odd thing. I cannot clear the AC code. It crashes the durametric software. So i thought that was real weird. 

 

EDIT* actually, i think i tried it once with ignition on and once with car running. Same result, i will double check that though with the car running though.

 

I have taken a few VERY short trips with the DME unbolted and it hasn't acted up yet. I will try a longer trip after i change the camshaft sensor. Still waiting for it to show-up and plan for it to take a while since the car will probably die again... haha

Edited July 22, 2016 by vosko

[Schnell Gelb]

" VERY short trips with the DME unbolted and it hasn't acted up yet. "

WAG - there is a fault to ground inside the DME case. When you unbolt the DME case from the structure of the car, you cut the faulty ground path.

[JFP in PA]

I am beginning to lean towards a wiring or DME internal issue.  P0335 is a lack of continuity (read it is unplugged) for the CPS; P0341 is for an alternating signal on the bank 1 cam position sensor; P1341 is for a discrepancy between the cam and crank sensor on bank 1 (which would be obvious if there is no CPS signal).  While all DME get warm while running, you should not be able to keep your lunch warm on it. The ABS and cluster codes look like communications issues as well.  It may be time to get a multi meter and start checking the DME to sensor wiring for continuity, and checking harness connectors for being either loose or corroded.  

 

Do you have a non contact pyrometer to measure the actual heat output for the DME?

[vosko]

8 hours ago, JFP in PA said:

I am beginning to lean towards a wiring or DME internal issue.  P0335 is a lack of continuity (read it is unplugged) for the CPS; P0341 is for an alternating signal on the bank 1 cam position sensor; P1341 is for a discrepancy between the cam and crank sensor on bank 1 (which would be obvious if there is no CPS signal).  While all DME get warm while running, you should not be able to keep your lunch warm on it. The ABS and cluster codes look like communications issues as well.  It may be time to get a multi meter and start checking the DME to sensor wiring for continuity, and checking harness connectors for being either loose or corroded.  

 

Do you have a non contact pyrometer to measure the actual heat output for the DME?

 

I have access to a thermal imager, will check the DME temps. Everything i have taken apart or touched looks in as new condition. That is why i am also leaning towards a DME issue. I am going to email ecudoctors and see if this something they can diag if i send it in. Maybe when its not 100 degrees outside in NJ, i can continuity test some wiring but that still doesn't make sense. Because why would it work fine until it warms up... 

[JFP in PA]

Simple: Resistance. If you have corrosion somewhere in the wiring network, the resistance will rise with the temperature, eventually reaching a level where things stop communicating, and systems stop working.

[vosko]

Just spoke to ecudoctors, i am going to send out the dme,immobilizer, and key to them to test. Will report back if they find a problem, only downside if there is a problem is the $675 to rebuild DME and more to replace the immobilizer......

[vosko]

Everything passed testing @ ecudoctors. Spoke to Porsche specialist and he thinks it might be related to the IMS.... 

[JFP in PA]

23 minutes ago, vosko said:

Everything passed testing @ ecudoctors. Spoke to Porsche specialist and he thinks it might be related to the IMS.... 

 

I seriously doubt it is IMS related, but to prove it, remove your oil filter and look for ferrous metal in large quantities.  No metal, not IMS related......