SamDaMan

Over the past three weeks I've gotten the white transmission run error twice. Both times the ambient temp was > 90F. Car was in Sports the first time, normal the next. The AC was on both times. Both times it continued to run Ok, except shifts were noticeably jerky. Switching the car off and then restarting brought everything back to normal. I've also had many error-free runs in between. All maintenance is up to date including the PDK service last year. Seems to have something to do with very hot ambient temp which are par for the course in DC.

Any ideas before I take it in? 2012 GTS cab at 60k miles.

Sam

stjoh

You need to hook it up to a code reader (like Durametric or PIWIS) and see what the codes are.

wjk_glynn

This thread (which is a sticky) has a tremendous amount of information about PDK issues.

https://rennlist.com/forums/997-foru...nsmission.html

sandwedge

Does it just say "Transmission run error" or "Transmission Emergency Run"? I've had the latter more than once and I'm pretty sure it was in red rather than white. Never heard of the one you refer to. Temperature may play a role but I kind of doubt it. On my second PDK 997 now and ambient temperature in southwest Florida is low to mid 90's about 6 months of the year.

How old is your battery? The PDK is hungry for electric power and old batteries have been known to cause issues. Why, I never fully understood or saw explained since it seems a fully functioning alternator should supply whatever power the PDK needs once the car is running.

92C2Targa#119

One or more Ignition module failure

PV997

There's both a white emergency run and a red emergency run. With white you can still drive for a short distance but there may be some gears missing, with red you are supposed to pull over immediately. Not exactly sure what triggers red but I think it has to do with fluid pressure or temperature as slipping clutches will be quickly destroyed.

Agree with stjoh, error codes are needed to make a diagnosis.

stjoh

It is well known that various engine issues (igniters, MAF...) can trigger PDK failure messages. If there is an engine related code I'd suggest you address that first as it may resolve the PDK issue too. Again, without the codes you're stabbing in the dark.

sandwedge

According to the service advisor at the local dealership, almost without exception these PDK warnings are electronics related and mechanically related warnings are very, very rare.

As I've mentioned, I've had three red emergency run warnings between two PDK cars. First one disappeared just by shutting the car down and starting it back up. Second one on that car was the end of that transmission. The light came on as I was backing out of the garage and then the car wouldn't move. Shut it down and restarted 4 or 5 times but no luck. Flatbed to dealer who told me the next day the PDK had to be replaced.

The third red warning came on the day after I had the 60K mile PDK service done on my current GTS. Car went into limp mode but I was close to my house and limped home. Again, flatbed to the dealer where they fixed it somehow. Suspect some kind of oversight during the service the day before.

Pulling error codes are all good and well and may allow them to repair in some cases. In most cases though, as in the case of the unit that had to be replaced, the codes they get are so general in nature that they don't lead them anywhere. That plus the fact that the dealers are so restricted in what they're allowed to do with these transmissions make the codes of limited usefulness based on what I've heard from the dealer.

SamDaMan

Codes came back indicating ignition coils.

P0352
P2305
U0146
U0155
U0401
U0418

Going to replace coils and plugs, battery needed a refresh anyway. PDK calibration after that and we shall see.

Any idea about those U codes above.

Thanks everyone.

byroncheung

@sandwedge what would be considered low resting voltage for our cars? my battery resting at 12.2V and I have been getting some PDK errors I wonder if it is battery related? Every time it comes on it's when I start the car but never in the middle of the drive so it makes me wonder...

GTSpure

Hi. How long is your car "resting"? In general it shouldn't be. 12.2v sounds low to me.
I would check for leaks / alternator.
Do you have a multimedia system or electrical products in the car (not original)?

GTSpure

Although this is a very old post, if someone has posted it, we would appreciate knowing if the matter is finally resolved for you.
Did the fault disappear completely after replacing the coils and battery?
Thanks!

byroncheung

@GTSpure I measured it this morning it has been sitting in my garage overnight (last start maybe 7pm last night).
All electricals are OEM. The battery is from 2018 Nov looks like so it's about 4 years old maybe getting toward the end of life?

GTSpure

2018 so I would start with a battery.

Floyd540

Let's go through a few fun facts regarding our car batteries.
Although we call them "12 Volt batteries", that is a complete misnomer but based on history.
A fully charged battery will measure 12.96 volts.
A few tenths of a volt is a big difference in these storage batteries.
Here is the one to surprise you. At 12.00 Volts the battery is considered clinically dead ,or "flat" for our European friends. If the battery is technically sound and only discharged to this value, it can be recharged.
A healthy battery , not under load, should measure 12. 6 to 12.7 Volts
A battery that gets discharged down to 10.5 volts may not take a charge and can be damaged beyond repair.
Fead acid, flooded, AGM, spiral wound (Optima) etc have a life span.
Your typical car battery ,flooded or AGM has a useful life from 4+ to 5+ years.
Replacing a battery should be a preventive Maintenace item like oil changes and filters, tires, etc. and done BEFORE problems show up.
12.2 Volts is a problem, a big problem.
Your car has thousands of dollars worth of electronics that require healthy, consistent DC power and that should be 12.7 Volts minimum.
When charging, the alternator will put out 14.7 Volts and 14.4 Volts will make it to the battery. This is good but don't get confused with this as it is under charging condition.
Remember that "12 Volt battery" is just a term.
Enjoy your new battery.