997.2GTS

My vehicle is all original, and has never had the PCM software upgraded. The current system version is 2.20 (I believe from 2011, when the car was sold). I just purchased an upgrade CD, as someone kindly provided the part number (26 cents!) and now I have an update CD from 2014 in front of me. And I hesitate. The only 'fault' that I know of with 2.20 is the A/C vent making a soft open/close sound after switching the car off.

What is the probability of bricking my PCM with an upgrade? I thought I would ask the collective to see whether someone else has had a nasty surprise after using an upgrade CD.

Wayne Smith

Risk vs reward ... what are you hoping to gain?

997.2GTS

Right - my point. All I believe I would gain is what I mentioned - the soft open/close I hear when shutting down would theoretically be gone. If upgrading was a slam-dunk, I would do it, but from what I read, you are rolling the dice somewhat.

Thomas_

Please elaborate regarding ”the A/C vent making a soft open/close sound after switching the car off”. I might have the same problem.

I have a 2011 997.2 C4S with PCM software ver. 2.20, and I can hear one of the aircon flaps go clap-clap-clap very soft and low volume, when I turn the motor off. Porsche says it might be the motor for one of the aircon flaps that’s faulty – but I am willing to try the upgrade on the PCM, if this could be the cause? I am in Denmark, so I would have to source the upgrade CD from somewhere.

997.2GTS

That's precisely the same issue I have with that version (2.20), you describe it well. The CD is available from many sources, search for part #: WKD-952-900-16

I'm unsure if there's a different version between Denmark and the U.S, but if you have challenges finding a copy locally, PM me.

Thomas_

Thanks, I will try to source the CD here in Europe.

Is it a known fix to upgrade the PCM or just a fix for some?

997.2GTS

That's the part I am unsure of. I do believe it is meant to fix it, as I recall during my online sleuthing that I read the A/C clap was a bug in 2.20, and was fixed when upgraded.

Wayne Smith

Modern cars with computers ... Pam's GLA45 goes through iterations of motors making adjustments for half an hour after a long drive. Something about removing moisture to prevent mold growth, checking for rain in case the sunroof needs to be closed, and who knows what else. It remains alive well after we shut it down.

My 2010 C4S also goes through different operations. Things mentioned in my first paragraph make me wonder if there are differences between coupe and cab. Anyway, I figure those after the fact whirls give the car a bit of its personality.

Petza914

I've learned not to mess with things that are working properly (especially software things) as it usually results in extra work to make it right or get back to where I started.

997.2GTS

Sigh. I agree, and after all this searching, retrieving, it's a desk ornament. At least I have it and as others said, it's the cheapest Porsche part I have ever bought.

MrMoose

So, don't blame me if you mess something up, but my understanding is that upgrades within the same SW family (1.x to 1.x or 2.x to 2.x) are pretty straightforward. Don't try to upgrade the maps, though, as that requires a key.

I'm brave and/or stupid and upgraded my 2010 PCM 3.0 with original "V" software to 1.47 and it went fine. I put the car on a battery charger just to make absolutely sure I didn't run out of juice in the middle.

https://rennlist.com/forums/987-foru...-anywhere.html

YMMV

997.2GTS

Thanks for responding. I hear what you're saying with minor versions.

Knowing me, it will be late one Saturday night, after one too many IPAs that I will have the "f*k it!!" moment and go for it.