PV997

Well folks looks like we've hit a roadblock. It now seems pretty clear that the major failure mode for these transmissions is the distance/gear shift/displacement sensor (known by all three names) as we've had about a half dozen failures over the last few months (P173x fault). It also seems pretty likely the failure is heat related as we've had a spike with the warmer weather. Last off, it's now apparent those claiming to have these on Alibaba or other Chinese websites are full of crap. Maybe they had a few at some point, who knows. So there are two options short of replacing the transmission.

Pressure ZF to sell these to the public - The part number for the distance sensor is ZF 0501 325 775. When I contacted ZF they told me they were forbidden by their contract with Porsche from selling these to the public. Perhaps a concerted effort (maybe from the PCA too) would make Porsche and ZF rethink this. Maybe legal action could be helpful but that's way out of my area of expertise. Something like small claims filings against ZF and/or PCNA for those who had a transmission replaced due to a P173x fault might be a tactic. Hopefully someone with actual expertise here can chime in.

Repair a failed distance sensor - This is an area where I do have some experience and I thinks it's probably very feasible. However, folks are reluctant to open up a transmission without a new part in hand (understandable) and there's also concern about reliability of a repaired sensor. Plus if someone buys a remanufactured transmission they need to send in the failed one as a core. So we are probably only going to get one of these to open up if someone buys a junkyard transmission as a replacement and we can pull it from the failed transmission.

So we are stuck for now unless someone comes up with a different idea or we can make one of these options happen.

Mrhobbiest

"Repair a failed..." I'll be all in with this once the code comes back. I have not driven since the gear oil change. Also waiting for oil analysis to return degradation report. No surprises in the gear oil when drained, just looked a little burnt/dark compared to the new oil. Obvious wear for 60K miles.

SamDaMan

So after a month of fruitless investigation, I went ahead and had the PDK replaced. So frustrating and anti-owner that Porsche won't allow for the distance sensor to be replaced. I had not choice given where the car is on the depreciation curve, but will say my brand loyalty has suffered a lot.

For others facing similar choices - pls call multiple P-car dealers to get pricing on the PDK replacement. The part numbers have changed recently and quite a few systems even at dealers haven't been updated. For my 997.2, the correct PDK part number ends in MX. It's an 18k job all in these days (i was quoted 20-23k at various dealers in the DC area) - apparently the PDK price is up 20-30% over the past few years. DM me with any Qs re the service.

Many thanks to PV997 for this great thread, and I hope you (or others) find a fix down the road.

Sam

Jon Bazansky

PV997 , thank you for putting together this comprehesive PDK transmission troubleshooting guide. This is a A+ professional written document !

To add some context to this failure on my 911 on Aug12th, 2020. I was driving from San Clemente CA (80 degrees F) to La Quinta (Greater Palm Springs Area (115 degree F). The Distance Sensor failed when the ambient temperature was 115 degrees F clearly a Extreme High Temp Environment. Had the vehicle towed to a Independent shop in Cathedral City, was told the distance sensor failed and the service advisor call around said Porsche will not allow ZF to sell the sensor direct to consumer and my only course of action is a PDK replacement for 16K.

I tried to source the Distance Sensor from Alibaba and another Chinese vendor with no luck "Sorry sold out" , sounds like the parts don't actually exist !
Has anyone been able to find a vendor that sells this Distance Sensor ?

It such a shame that my only course of action to repair a 911 PDK transmission with less than 50K miles with an ENTIRE 16-20K transmission replacement due to a sensor failure !

PS- My brand loyalty has been tarnished Does anyone have any statistics on how many distance sensors have failed in the PDK product line requiring a new transmission install. I am going to write a letter to Porsche and also BBB-consumer protection. Probably won't get anywhere but as owner of 3 new Porsches over the past 15 years, It will be Good Therapy to mitigate the abuse of a loyal consumer for the Porsche Brand, clearly "There is no substitute for a 50 dollar distance sensor !

PV997

Thanks Joe, appreciate the kind words and I'm sorry you got stuck with this. Please keep us posted on how it goes particularly if you start to get anywhere. Just a thought, what if you sued the dealer that did the transmission switch in small claims court for failing to use a replacement part? We know the part exists and is available (to mother Porsche at least) so the argument would be the dealer was negligent in not using it. The only way we are going to get these available to the public is through pressure. Dealers getting sued (even though a win is unlikely) is an possible avenue. The dealers are constantly saying "parts are not available" which is a completely untrue. Parts are "available" but restricted due to the Porsche cartel.

I can tell you guys that if my distance sensor fails it's coming out and I'm going to try and fix it. What is there to lose? I DIY everything and my car is not a DD so I will give it a try and hope others will also consider it. The transmission has to come out anyways for replacement, is pretty much a paper weight at this point without repair, so why not crack the case and take it out? Again, what is there to lose?

Now that it seems pretty clear this failure is heat-related (based on both the rash of summer failures and the electronic component susceptibility) folks who track their 997/987 or live in a very hot climate really should consider an aftermarket gear oil cooler. Porsche added one to the 991/981 in 2013 and I'm convinced they did so after seeing early 997/987 distance sensor failures under warranty. They aren't cheap but a DIY install can get it done for about $1k.

Doug H

If you have purchased 3 new Porsches, call PCNA. They may help out with some goodwill.

Jon Bazansky

Thanks for the recommendation. I am not a big fan of litigation, extremely time consuming and usually outcomes are not positive for either party !
I am going to see if I get anywhere with PCNA ! Perhaps, I can get a reduction in cost for a PDK replacement and save 50% of the cost of a new transmission. Let's see if Porsche has any good faith with their loyal customers

PV997

Yeah completely agree. I'm an engineer but come from a family of lawyers so it's in my blood, but I'm not a fan of litigation myself. Full disclosure - I have absolutely no idea what I'm talking about in this regard so maybe others can help.

I'm tired of seeing comments or getting messages from people who've been hit with a $14k bill for a remanufactured transmission when the problem was a $500 part. These parts are available, we know what they are, we know the part number, but Porsche refuses to let their supplier sell them. They have created a cartel around these transmission parts for no good reason other than to set up a racket (i.e. throw maybe a few $k in parts/labor at a "failed" transmission and resell it for $14k as remanufactured). Some VW executive decided to do this as policy, it was not an honorable decision, and they won't change it unless forced to do so. Legal action (via owner lawsuit or consumer protection action) is the only thing that will change things IMO.

Agree with Doug you should follow up with PCNA and maybe you could get some help for your situation. From a bigger picture perspective what do we do to get Porsche to change their policy? Believe me, I definitely want to get my hands on a distance sensor and fix it to post how-to instructions and photos all over the internet. These types of screw jobs tick me off and it would make me very happy to undermine it.

mchrono

how hard would a distance sensor be to reverse engineer and reproduce?
Id bet it wouldn't take much longer or cost much more than litigation.
Then you can make a little business out of it.
Remember the IMS bearing replacement cottage industry?

Antoine Caby

Thank you so much for this amazing thread. Driving a 2012 991.1 in France, I experienced the same faulty distance sensor issue and ended up in paying for a a refurbished transmission, despite battling with Porsche during 5 months, incl execs in Germany. How Porsche is managing this is an outrage. With aging 997 and 991s, the problem can only get bigger with an increasingly unacceptable cost. This affected a life long brand loyalty and bitterness just isn't going away... reading this so well documented thread eased the pain a bit though ;-). One question: has anyone come across similar discussion/forum in Europe ? Thank you and drive safely.

subaru335i

This is discouraging. I have a 2014 991 and was hoping the gear oil cooler would help prevent this issue but I guess not?
France isn't even very hot so I am surprised by your failure.

Antoine Caby

Actually that happened last summer after 2 weeks of really hot weather... I seem to match the classic pattern....

David Barber

Keeping this thread alive. I own a 987.2 PDK and would like to see this keep moving.

Do we have a log of all PDK failures? If not I'd like to create a web-based log and socialize among Porsche owners. I am thinking we could capture year, model, mileage, symptom, cause (if known), and cost of repair.

Cheers,
-db

PV997

I have not been keeping records but here is my very unofficial tally based on what I've heard about since I put this thread up in December. This might be helpful in understanding relative frequency of occurrence but we can't draw any absolute rates from it.

Failure type:

• Distance sensor: around 8 (P173x fault)
• Speed sensor: 1
• Clutch fluid pressure sensor: 2
• Valve body solenoid: 3
• Temp sensor: 2
• Clutch failure: 1
• Other mechanical failure: 2 (bearing, seal)

Again, this is from memory and isn't meant to be precise, if anyone has more accurate numbers please let me know. I'll have to update the post as when I wrote it I though the solenoids were the most frequent failure when it's now clear it's the distance sensor. Most of the failure reports have been 997/987 but I have no idea if it's significant. There is only one 991/981 distance sensor failure that I recall (recently reported by Antoine) but that may be reporting bias since this discussion is in the 997 forum. If folks know of others please mention them in the comments.

997ajk

Good read, that's related to DCT/DSG tranny from VAG..

https://www.team-bhp.com/forum/techn...t-gearbox.html

I spoke to a Porsche contact he suggested that PDK failure rate on 911/Cayman is around 6% in first 100k miles and 27% by 200k miles.