There is no way to rule out wiring.

Pedro (and others): if you would, please take a look at the link below for the problems I'm having with my 2011 Cayman. Let me know what you think is going on.

Thanks,

[www.planet-9.com]

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Some people can get away with cleaning them, although at least one experiment has shown they can still work in a dirty environment, but on my former (2001) Boxster, the MAF eventually got changed out after all four O2s and MAF cleanings didn't endure. The car now has maybe another 10,000 on it with no codes. Oh, the car had about 95k on it at the time, but that's with a factory replacement motor that was installed at about 48k. Without considering other factors, that engine and yours are in approximately the same mileage range.

Thanks for that tip. Pardon my ignorance, but what does MAF stand for?

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Here's a great article on MAF, found it quite instuctive...

Pelican Technical Article on MAF

its what measures the volume of air (oxygen) so that the right amount of fuel can be metered to the motor.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

I would begin at this point by having a 2nd measurement point - e.g.: run the car and see what an exhaust gas analyzer says. Maybe zero O2 sensors were bad.

I'm not sure how the computer determines that an O2 sensor is bad. It could get an implausible signal, maybe. I guess the question is, how does it measure the result? What in THAT chain could malfunction?

This is the problem with simple error codes. It eliminates thought. 99% of the time that's an improvement, but the other 1% of the time it causes trouble and dead ends.

My experience is that the 02 sensors and cats on these cars (and most others) are very dependable. Moreover, failures are generally gradual as they go out of calibration.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 05/26/2014 04:08PM by grant. (view changes)

That is correct. They chalked up the first failure to a part failure - a bad o2 sensor.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Grant

gee-lenahan-at-gee-mail-dot-com

... that the techs don't really have a whole lot of experience.
They're really young and they're taught to follow the computer's recommendations blindly.
Pinpointing particular issues can be tricky because the error codes just point you in the right direction.
No sh!it it's emissions related! Whenever the CEL is on solidly it's emissions related by definition.

I would first testb the DME befor I start going pin-to-pin on the wiring harness.
To test the DME it's really simple. Just swap it with another one from the same model year.
Drive it 20-30 miles and if the CEL stays off ... it was the DME.

I highly doubt that it's an O2 Sensor that's gone bad. Highly unlikely with less than 50K miles.
It may be in the O2 Sensor's connector or wiring harness.
Without the actual codes it could be a million different scenarios.

Let us know what they find.
Good luck
Happy Porscheing,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

"Fuse holder, fuse,
connections and splice junctions all good. Currently reprogramming DME
computer. Porsche is closed today stateside."

What do you guys think? What does reprogramming the DME do?

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

It sounds like they don't know what they're doing.

Can you find out what all of the codes are?

Also, it's entirely likely that some mistake made during the service prior to the problem caused this. Maybe it's a pinched wire that is intermittently disconnecting. That could easily pass the wiring test. I would look back at what was recently done to the car for clues.

Grant

gee-lenahan-at-gee-mail-dot-com

Only recent service was o/f change at 40k. Was going to do 40k service at 50k.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Pedro - how do you feel about today's news that Porsche has approved replacing the DME? With other potential causes ruled out (O2 sensor, wiring, reprogramming the DME), will a new DME finally fix it in your opinion? My understanding they don't have another 2011 Cayman that they can pull the DME out of, and test. Look forward to your thoughts.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

you post the details here? Error codes and so on.

Has the car sat unused for a while? Whenever inexplicable things happen I always think of rodent damage, rodents (mice mainly) having been at the car during a lay up. The car doesn't have to sit long unused. A couple of weeks even less in some cases.

Generally the rodent sign is rather obvious but not always. If they were just in the car exploring and didn't set up housekeeping all one has to gone on is gnawing marks on wires, hoses, maybe patches of carpet missing (makes for a cozy mice nest) and droppings.

The Cayman is my daily driver. Has not sat idle or unused for longer than a day.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Tuesday update: despite reprogramming DME, CEL light still present. Service Mgr. sent VAL to Porsche. Requesting authorization to replace DME. Will update me Wednesday.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)



Edited 2 time(s). Last edit at 05/27/2014 08:44PM by YoungTurk. (view changes)

That is disturbing; when I see this kind of plug and play to fix a problem, it seems they are just grasping at straws.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

not sure I understand the question.

From your posts so far, it seems Porsche has been busy trying to identify and fix the cause of the problem, under warranty.

What sort of 'compensation' are you thinking about?

Porsche Customer Commitment said Porsche "wanted to compensate me" for all my trouble once my car is fixed. What do you think that compensation will be?

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

That's impressive. I have no idea what it would be. Maybe vouchers for the purchase of accessories? A week at a Porsche track/driving school would be cool.

Or one of those trips to Germany to drive around in a 911 for a week would be awesome, but likely not in the cards.

are easy to understand (most of the time) compared to a large bundle of wires that tie all the car's subsystems together with the DME and other controllers.

(At work the other day I had a micro controller on a test fixture board act up and get into a goofy state. Couldn't reprogram it. Couldn't erase the image in it. Couldn't change the fuse or lock bits.Tried everything. A bit of online research found mine was not an isolated case. At least one "solution" or work around was offered but it didn't work out. The tech had to unsolder the old micro and solder on a new micro, a different one (though it was pin compatible with the old bad micro), but thankfully a new one that has an emulation mode for the old micro so I didn't have to rewrite thousands of lines of code to adapt the code to the new microprocessor.)

In the case of the OP's car the techs are probably acting upon instructions from at least PCNA and probably straight from the factory. The factory has a series of steps or things to replace until either the symptoms go away or it comes down to (probably) dropping the engine and replacing the engine wiring harness.

Tuesday update: CEL light still present, after reprogramming DME. Service Mgr. sent VAL to Porsche. Requesting authorization to replace DME. Will update me Wednesday.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Will replacing the DME resolve my issue?

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

But as i stated above, the first thing one has to do is understand the mechanism for determining if the O2 sensor is faulty.

next,see what is in the chain. any one of them could be the problem. DME code, a wire, the sensor itself. on method is to measure sensor changes in response to mixture changes ( measured at the FI). Then any metering error would be part of the problem. That's why i find this thread missing much in the way of logic: first, someone has to chase the circuit, then see what parts are in it, then look for errors.

They seem to be throwing parts at it. Typical.

I certainly cant tell you if the DME will fix anything. It might, but maybe not.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Service Manager just called first thing this morning, with the "good news" that Porsche has approved replacing the DME. I asked if there was one stateside. Yes, there was, with ETA at dealership tomorrow, exactly three weeks from date my Cayman was first towed from my home. Asked service manager if this was it, if replacing the DME would resolve my issue. Said yes, he has "every trust" that it will, because that's what Porsche is telling him. Its just that as he explained, they had to eliminate the other potential causes like wiring before agreeing to replace the DME. I'm cautiously optimistic. Please tell me its well placed.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

FWIW (which may not be much, as I don't have nearly the mechanical knowledge of many posters here), I'd hazard a guess that you're not wrong to be cautiously optimistic. 3 weeks of downtime sucks, but they do appear to be trying to sort it out.

Hope the news will be good once the new DME is installed.

Don't be too disappointed if the new DME doesn't solve the problem. In my career before retirement I spent over 40 years troubleshooting electronic hardware and software. I would guess the problem is more likely physical than electronic. Let me explain. The car has been functioning well for over 48K miles, in Texas, where it gets hot. I would imagine an electronic glitch would have occurred before now. A physical problem such as a faulty wiring harness or connector would be more likely to occur over time. The problem seems to be intermittent which makes it hard to track down. Techs use tricks like a heat gun (powerful hair dryer) or freeze spray to try and isolate a problem like this. Since my 2010 Boxster shares many parts with your car, I am more than casually interested in the root cause of the issue.

True, but Porsche had the dealer rule out wiring as the cause (which it did) before agreeing to replace the DME.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

1. short of pulling the entire harness and replacing it
2. you cannot prove a negative. It is logically impossible

They, for reasons they have not shared, think its not the wiring.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Well this tempers my optimism which I guess is good.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

I hope the DME solves the problem, in which case I would guess it would be something like a connector in the DME. If it doesn't, a reasonable next step would be to replace the wiring harness, which I am sure would be a labor intensive process. I wouldn't trust the Porsche dealer to track down an intermittent failure in the wiring harness. They could send the old harness back to Germany for analysis if that solved the problem. You might mention in an appropriate way to the dealer service department that there are hundreds of current Boxster and Cayman owners on internet forums waiting to see how this turns out.

to track down a problem with the harness. This can turn into a very expensive task and one that has some risk of delivering unsatisfactory results.

If testing and what have you eliminate other possible explanations the harness will (probably) just be replaced. The suspected defective unit will shipped back to the factory (probably) for analysis.

But maybe not.

It is not like wiring harnesses are failing right and left and Porsche -- along with every other car maker -- puts a lot of trust into its wiring harness supplier and the supplier/maker relies on its processes and inspections to ensure a high rate of trouble free harnesses.

The days of sitting down with a wiring harness and a volt/ohm meter and tracking down a harness problem are long gone. And thank goodness.

Dealer installing & programming now.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Fingers crossed, YT.

Service manager called early evening Friday, breathless, happy to report that we're good! He drove the Cayman about 80 miles. Stopped it, Started it,

And no light!

Picking it up about 9:30 this morning.

After 3 weeks and 2 days, I feel like I'm getting a new Cayman all over again.

Will update later today

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Quote
YoungTurk
Service manager called early evening Friday, breathless, happy to report that we're good! He drove the Cayman about 80 miles. Stopped it, Started it,

And no light!

Picking it up about 9:30 this morning.

After 3 weeks and 2 days, I feel like I'm getting a new Cayman all over again.

Will update later today

That is good to hear! Let's hope that light stays out.

Glad its fixed, but i wonder...
Unless overheated, badly jarred, or made wet, modern electronics dont just fail often.
Mechanical parts like switches and rotary controls do,but there are none on the DME box.

So, for us all to learn something i wonder what might have occured? Could it have gotten wet? The connector been hit in another service? etc.

Just wondering.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

If the error codes pointed to an O2 sensor probably one related to the analog to digital converter portion of the DME. Many sensors are connected to the DME at an input pin that leads to the A/D peripheral of the DME. Converting analog voltage levels into digital values so these can be used in calculations to manage the engine is a lot of what the DME does.

While you are right that modern electronics just don't fail often, they can still fail. The OP's car is an example of that.

A very unusual failure mode. Most electronic modules fail completely for a variety of reasons. Intermittent failure is very rare. My money would be on a cold solder joint.

then but something else and a cold solder joint is as good as any an explanation and better than most.

So far so good guys. Heading on a 300 mile road trip today so I'll have a full update later, including quotes from the service records.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Well, after 2 days and about 400 miles, WE'RE GOOD. No more issues.

The tech explained why the DME failed but honestly it all sounded Greek to me. What I do remember him saying is that there was a "driver failure" and it was intermittent.

He said the DME alone (just the part) cost $7,000.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)



Edited 2 time(s). Last edit at 06/02/2014 07:36PM by YoungTurk. (view changes)

Just kidding. He must be talking about a software (driver) glitch. I wish I had heard his explanation. I'm curious.

that would based on the report intermittently fail to put the proper voltage level on an output pin.

It is as I suggested in an earlier post the (intermittent) failure of an electronic component (possibly a pull up or pull down resister) of an output line of the DME.

This is all very good news for the rest of us. This failure is not likely to occur again. I previously owned a BMW Z3 and there were well known wiring issues that occurred over time reported on several forums. I personally was very happy with the outcome here.

Glad to hear the fix is working.

OTOH--$7K for the DME; that sounds incredibly expensive.
Had a discussion about this topic today with a local Indy and he lamented that given trend of replacement parts costs on cars like BMW/Porsche & MB, many of these models will be prohibitively expensive to keep on the road.

Mike, you're right about the cost of maintaining today's 'sophisticated' high-end cars post warranty.

My E39 wagon has an 'old-fashioned' manual tailgate. It's easy to open and close. I lube it from time to time, hoping it will respond with continued longevity. It will be14 years old, next month.

My brother's E61 (which recently came off warranty) has an electric/hydraulic push-button tailgate. Last week, the small ball which joins the hydraulic strut to the body broke. The ball isn't available separately. A new strut is setting him back $1400 Cdn, not including labour. The non-motorized strut on the right hand side - that's $73.

Self-closing doors, trunk-lids etc. All these little motors are great, until they break. And break, they will. It makes a strong case for leasing, but for those of us old-schoolers who believe in owning our cars, leasing is a hard pill to swallow.

For my inconvenience in being without my Cayman for 3 weeks and 2 days. PCNA sending voucher for $1k for parts, service, etc. from any Porsche dealer.

Well done Porsche. Very pleased.

2011 Cayman (Platinum Silver/Black)
Previously owned:
2001 Boxster (Seal Grey/Black)
2005 Carrera Coupe (Arctic Silver/Black)
2005 Carrera Cab (Arctic Silver/Stone Grey)

Now, about that DME pricing--they gave you a price of $7K ? Was there any more discussion on that subject--like why it was so expensive?

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna