Balr14

https://rennlist.com/forums/991/1214...up-switch.html

sandwedge

The "light" was a precursor to pdk replacement on my -09 C4S but not on the GTS after it came on just after the 60K mile service. So based on about 80K miles on two 997 PDK cars I don't think one could draw any hard and fast conclusion either way what the transmission emergency run light signals. In my case it's been a sign of bad things ahead but it's also been a sign of nothing to see here.

As for the comparison between M96/97 engine issues requiring rebuild or replacement and PDK replacement I think it's a point well taken to the PDK alarmists. There was a Rennlist poll on IMS failures which stayed on for quiet a while at the top of the page. Haven't seen it in a while. The failure rate was somewhere around 5% and 6% as I recall it. And that didn't include bore scoring.

Haven't seen a PDK failure poll yet but it's rarely brought up so mine may be one of very few or people just aren't talking about it which seems unlikely given the cost of replacement. Which has come down quiet a bit. I think you can get a factory rebuilt PDK now for close to $10,000. Compared to a new or rebuilt M96/97 engine in the $20,000 to $30,000 range depending on which way you go.

Doug H

I am definitely not trying to push pdk over manual although I think paddle shifting on the steering wheel is much more at home on real high performance sports cars.

The M96/97 failure rate is out the roof. Sadly, someone combined the 997.2s that gave no IMS with with the 997.1s. Add that to scoring and all of the other catastrophic engine failures in the 997.1 and it’s a black mark on Porsche brand IMO.

Look, my only point was it was incongruous to whine about pdk failure rate when you are willing to drive a NA 997.1 with a MUCH HIGHER failure rate and that cost much more to address.

robert_ny_cars

I received the dreaded phone call that the Electronic Control Unit replacement did not fix the errors. The checklists which are well known to other posters are being followed but barring a miraculous recovery, a new transmission will need to be ordered. As other posters have commented here, all checklists lead to replacement.

I am hoping that there will be a new transmission stateside available to be put in quickly.

I still love Porsche in general and this car in particular. Everything will be covered by CPO. Afterwards, we will definitely look at that Fidelity Warranty. Right now car is at 30,500 miles. I understand there is a cost to ownership of such a special car. I hope to be able to post the sub codes in the future not just the general P0700 in an effort to help everyone understand what is it that goes bad in these transmissions and hope that one day the problem can be remedied. As was widely pointed out it may not have been such a bad failure but the prescribed process leads to replacement.

Looking back this issue was not known to anyone - the car passed CPO inspection at around 26K miles with flying colors and there were no errors at the 30K tuneup.

I still think that the 997.2 with PDK is a blast and mind blowing experience when you accelerate. With CPO / Fidelity warranty there is not much to worry about.

Thank you to everyone that provided information on the thread. I hope to celebrate soon when the new transmission is in!

PV997

Wow, sorry to hear that. I would not pay out of pocket to do this and would dig much deeper (but my car is not a DD, I have a PIWIS, and a lot of docs/info on the PDK). However, Porsche dealers aren't set up to do that and I certainly wouldn't turn down a new transmission for free. They giving you a loaner?

robert_ny_cars

@PV997 Thanks for the support. I just use my other car for daily driving so I didn't ask for a loaner.

sandwedge

The PDK that failed on my -09 C4S was replaced in 3 days. My service advisor said Porsche keeps a healthy inventory of replacement units in a warehouse in Atlanta and mine was trucked down to Florida overnight following the diagnosis. I'm sure they have replacement units at other locations in the country. That said, this was 4 years ago so things may have changed but that's how it worked out for me.

robert_ny_cars

The dealer contacted PCNA and were instructed to check the wiring and electrical systems one last time to verify that there is no electrical problem in the car that would be triggering the errors. After that, the transmission replacement got approved, but it will need to come from Germany which will take a while. I'm excited to drive the Turbo S again once it gets the brand new transmission! Thank you for the support everyone!

Floyd540

I am guessing, (like everyone else) that the problem is a failed signal from one of the shift rail position sensors (hall effect I believe) that is buried in the center of the transmission and not accessible from the outside as it should be. It is an electrical sensor and subject to failure just like cam position sensors. With a bad signal (bad sensor, internal wire broke or failed mounting , ) from a shift rail sensor, the TCU is going to stop the game. Audi had some of these issues. Inexpensive electrical part, hard to get to. Could be something else. Hope you get it worked out to your satisfaction. Best of luck! (really)

PV997

If it is the distance sensor (shift rod position) there would be a P173x code stored, I don't think this is it based on what the OP described upthread. I'm not at all surprised Mother Porsche wanted the dealer to dig into it more before replacing the transmission as the symptoms don't sound right. It sounds more like a communication issue with the TCU although replacing the TCU didn't fix it. Replacing the transmissions without more solid information seems like throwing parts (expensive ones) at the problem. I hope it fixes it. Did the dealer ever provide a more detailed fault log?

Upscale Audio

My 991.1 PDK failed at 9877 miles. While it was in the shop I was bitching to a customer of mine that they were replacing it with a rebuilt and his PDK failed in the first month on his 911TTS. It do happen.

997Lyfe

Is the shift interlock solenoid replaceable in these PDKs if they die? It wouldn't allow you to shift out of (P)ark. Anyone have this failure? Mine has started to click louder and don't know if that is a precursor to a failure

Steph1

​​​​
They sure do, reported here before that I have 2 acquaintances that have had 3 PDK failures in their 997.2. 2 while under warranty and one guy had it happen again while one out of warranty!!! My indy's boss just bought a super nice spec'd 2013 Carrera S with PDK and his PDK just failed while on the highway a few weeks back. They were working on it when I left the garage from getting my Q5's oil changed. Reminding me that I should call back to see if a replacement was required.

​​​​To the OP, hopefully they get it fixed or repaired quickly. Don't know where you are, but here, I should be storing my car this coming weekend, unless long term forecast gives me hope.

robert_ny_cars

The transmission was replaced for a new one! The 911 is back and we enjoyed driving it! There are no errors at this time. I really appreciate all of the detailed ideas from the board, which allowed me to understand the intricacies behind the transmission itself. There was no charge as this happened under CPO. It was surprising to me that there was an oil leak discovered and also that the transmission fluids were noted to be low so soon after the 30K inspection at another dealer.

Recap from the service statement.
There was an initial normal road test with no warnings.
"Performed diagnostic fault reading. Vehicle has fault for transmission temperature and pressure sensor. Diagnostic flow chart PS3 9x7 for Turbo PDK followed."
Performed transmission clutch fluid check and filled 370235.
Performed transmission fluid check and filled 340135.
Both fluids were low at time of inspection. Filled cordially to manufacturer specs. Less than 0.5 Liters. Also checked for any sign of leaks on the transmission pan or around the transmission housing. Erased all faults and attempted another road test.
When pulling off the lift, transmission failure light appeared.
Check if electrohydraulic control unit was replaced. No history on PCSS.
Flow chart indicated to replace the electrohydraulic unit.
replacement of electrohydraulic 38775500.
Performed trans calibration.
Performed trans fluid filled and check.
Transmission warning displayed again. Erased codes. Performed another road test. No problem during driving but when pulling into service drive, transmission fail warning light came on and no reverse gear available.
Checked connectors on transmission for proper tension.
removal of interior to access control panel.
check connection to control unit connector - clean pins.
transmission replacement
transmission coolant valve and clip transfer to new transmission.
transmission reinstalled with cross member and cover installed.
VAL before calibration instructed by tester.
transmission set to temp to performed calibration 30-50 degrees Celsius. Calibration of transmission, two failed attempts, succeeded at third attempt.
reinstall vehicle interior.
check transmission oil level for clutch and transmission. Performed fill 370235 and 340135.
extended road test.

Tech noted oil leak
15551904 hydraulic valve for valve lift adjustment removed and reinstalled
999-707-404-41 O-Ring
During MPI found oil dripping from Bank 2 cam adjuster. Vehicle requires cam adjuster O ring replacement which was performed.

Parts
9G1-317-015-00 Control unit, hydraulic
000-043-305-13 Transmission oil PDK (9 units)
9G1-321-025-01 Oil Sump
9G1-321-801-00 Torx Head screw (13 units)
9G1-307-891-01 Seal ring
000-043-305-49 Transmission oil manual (1 unit)
9G1-300-021-CX transmission

PV997

Thanks for posting this. For some reason despite all that detail in the report above they never state what the actual failure codes were, they just say they were cleared. Weird.

Looks like they tried to replace the valve body first (aka hydraulic control unit) but that didn't work so they replaced the whole transmission. This is different from the TCU (electrical control unit) which may have caused some confusion upthread as it doesn't look like the TCU was ever replaced based on the report.

Based on their use of flow chart "PS3" it almost certainly a failed clutch fluid pressure sensor (the documentation lists the associated failure codes that led them there). As usual with Porsche PDK documentation, the flow diagram takes you "replace PDK" if simple measures don't fix it. Here's the thing though, even though Porsche provides no work instructions on how to replace these, the parts are available and easily replaced after dropping the PDK! We've had two commenters over in the PDK sticky that replaced these and fixed their transmission. This was after one of them was told by the dealer it could not be replaced.

Anyways, glad you got a new PDK and everything worked out ok under CPO. If anyone does not have a warranty and this happens, go read the PDK sticky before shelling out 20 grand!