987.2 S Failed DME/ECM

[dbarber]

Hey everyone, not the greatest first post, but here goes!

 

My car melted both catalytic converters last time it was on track (I only track it 3-5 times/yr., and it's not full track setup). Long story short, it ended up at a trusted Indy who diagnosed the failed cats. After replacing the cats, the car still didn't run right, stalls, and has limited power. The only code stored was for crank/cam deviation, so that's the troubleshooting direction they took, thinking that maybe the timing jumped on one bank, or the camshaft actuator failed or had clogged oil passages. I wasn't 100% on this given both cats failed, not just the one on the bank with the code, but they assured me this was the process to take. Now, after removing/replacing the engine and finding nothing amiss, they think DME/ECM has failed. However, they're stating my car (2011 Cayman S) has a super-rare DME for which there are no replacements in stock, and the lead time is several months. I'm not seeing this reflected in part numbers for DME's on various parts sites. Has anyone come across this rarity or specificity of DMEs/ECMs based on the manufacturer? it should (IMO) just be a part built to a spec. I'm really struggling to process this (both the troubleshooting steps and the rare DME). Any input appreciated. FWIW, I am technical and versed in general diagnostics. Thanks!

[Loren]

Did they try re-programming the DME?

I have seen that re-programming can cure a "mixed-up" DME.

 

What are the current fault codes?

[JFP in PA]

11 hours ago, dbarber said:

Hey everyone, not the greatest first post, but here goes!

 

My car melted both catalytic converters last time it was on track (I only track it 3-5 times/yr., and it's not full track setup). Long story short, it ended up at a trusted Indy who diagnosed the failed cats. After replacing the cats, the car still didn't run right, stalls, and has limited power. The only code stored was for crank/cam deviation, so that's the troubleshooting direction they took, thinking that maybe the timing jumped on one bank, or the camshaft actuator failed or had clogged oil passages. I wasn't 100% on this given both cats failed, not just the one on the bank with the code, but they assured me this was the process to take. Now, after removing/replacing the engine and finding nothing amiss, they think DME/ECM has failed. However, they're stating my car (2011 Cayman S) has a super-rare DME for which there are no replacements in stock, and the lead time is several months. I'm not seeing this reflected in part numbers for DME's on various parts sites. Has anyone come across this rarity or specificity of DMEs/ECMs based on the manufacturer? it should (IMO) just be a part built to a spec. I'm really struggling to process this (both the troubleshooting steps and the rare DME). Any input appreciated. FWIW, I am technical and versed in general diagnostics. Thanks!

Welcome to RennTech 

 

The 2011 car would carry the SDI version DME.  Failures of these units are pretty rare unless they have been tampered with (to Loren's point), which is a good thing considering the cost of replacing one.  At this juncture, I would get all current and pending codes as a starting point; even the DME has a code for when it fails, so those codes are important.

[dbarber]

Thanks for the replies and the welcome. I'm not sure if they tried to reprogram it yet. I'm going by today to talk to the shop owner and tech. The car had a softronic tune for about a year prior to the failure, and the shop had me reflash it back to stock before troubleshooting. The weird thing is more the lack of codes. Initially the only code was a generic "value out out of range" but nothing else (according to my Durametric). Other than that, nothing. I was hoping they would use a piwis and find more clues, but they didn't find anything except the crank/cam deviation that appeared afterwards and has been a long time gremlin.

 

When I used my Durametric before taking it in I looked at fuel pressure and misfires, suspecting the hpfp, and the data was really weird. It was only reporting 4 cylinders. I chalked that up to a bug because I had just updated the laptop. 

 

 

Edited September 7, 2022 by dbarber