The reason it always occurs at that point is the engine is warmed up identically by the time you reach that point, so the conditions triggering the fault are the same.

Quick answers:
1. It won't fix itself. It will get worse and will affect the driveability and fuel economy of the car. It has to be fixed.

2. Find a shop that lets you make an appointment and bring it in the night before (so the engine is cold, and easier to work on..) Do these shops expect you to park the vehicle at their shop until they get around to it? If so - find a real shop that schedules their time.

Longer answer: Fix? The valve timing solenoid can be removed and cleaned. There are actually two of them. One does valve timing, one does valve lift. If it's the valve timing error message - that one is under the valve cover on that bank. It can be removed, and flushed with some cleaning solution, opening by using a 9V battery, just click it open a number of times until the cleaning solution flows through it. A good shop will know how to do this, and make sure they have a quick source for a replacement if cleaning it doesn't work.

The other one (valve lift) is in the back of the head... it can be accessed without engine removal (although Porsche may try to inflate the job telling you the engine has to come out.) Depending on which bank, either the vacuum pump or the high-pressure fuel pump must be removed to reach it. It unscrews. The replacement from Porsche is a few hundred dollars. The identical valve can be had aftermarket for a fraction of that price, and a reputable shop I used said they're identical (and the same one that 911 engine use for the same thing..)

Or you could try running some engine flush through and see if that cleans it out. You only want the engine flush in there as briefly as possible, so you'll be changing the oil IMMEDIATELY after doing the flush.

BTW - if you've been doing factory-recommended change intervals (10k miles) this is a good reason not to. And Mobil-1 despite being "recommended" by Porsche isn't the best oil in the world. But you can explore oil options yourself - lots of opinions, and a few facts are out on the web.

 

Thanks for the info. Yeah, the Euro garages here are in high demand and they know they can just make people wait.

I did do an engine flush with two containers of the Liquimoly, just let it run for 15 and immediately changed the oil but that didn't help obviously. I've only had the car for about 6k miles but the carfax indicates 10k mile oil change intervals. My plan is to change every 5k, and I may switch to Synthoil which is what I use in my 996 (only because that's what the last guy used).

I had an appointment to drop it off at a different shop tonight, but the CEL light has been off since Sunday. They said they would still look at it, but suggested I wait until the light comes back on which is what I plan to do. They may be hesitant to dive in and start doing work without being able to verify the code, I'm not sure. This very well could be the first Cayenne S they have worked on. It's not easy finding a Porsche mechanic in a smallish city.

 

I had an appointment to drop it off at a different shop tonight, but the CEL light has been off since Sunday. They said they would still look at it, but suggested I wait until the light comes back on which is what I plan to do. They may be hesitant to dive in and start doing work without being able to verify the code, I'm not sure. This very well could be the first Cayenne S they have worked on. It's not easy finding a Porsche mechanic in a smallish city.

Despite the light going off - the codes are still stored in the modules and will be there until someone erases them. So they should be able to satisfy themselves on what is going on with the engine. The better diagnostic tools will even tell them how many times the fault occurred.

 

Hi, wondering if you ever found the proper fix for this and what was done? I just purchased a 2016 Cayenne Base that has the same soft code P005C2B and 2F which reappears after clearing on scanner. Car runs fine presently. Thanks.