subaru335i

Hey Wesley, You say you replaced the sensor but how did you get the replacement sensor?
Or did you also repair the old sensor?

We are having trouble finding a source of the sensors themselves so I thought we had to resort to rebuilding them ourselves.
Hopefully you have a line on replacement ones, I would much rather just swap in a brand new sensor than a hand rebuilt one (but would do it if I had to).

PV997

I have not chatted with Wesley but did exchange emails with a big transmission shop in Asia. Apparently there were some replacements available from China at one time but now no one has them. I don't know if they were remanufactured or if someone got a bootleg shipment from ZF. Agree it would be much better to replace them than repair them if they are available. If there is a supply it's very unsteady and not a reliable source from what I've seen.

JC Lacayo

Following because this is a great thread. Thank you all for sharing.

PV997

This is a great idea. Anyone have contacts in the motorsport community that can follow up on this? Might be better for an insider to contact them rather than a yahoo like me who has never dealt with them. If technical details are needed send me a PM.

steve0827

Going to PM you. Have great contacts.

fraazz

Tried to message Wesley on here but it won't let me. I see other people are having the same issue on this forum. I also do not have instagram.

pfbz

What a superbly written and incredibly informative thread! Thanks @PV997 for all your efforts! Gives me more peace-of-mind keeping my 991.1 Turbo S (which is accumulating plenty of miles) when the CPO expires.

Full-unit replacement is great when cars are under warranty... Honestly I'd rather have the Porsche factory 'fixing' internals than a local dealer shop tech, but obviously that isn't a great situation post warranty. I'm betting some shops will sprout up over the next few years specializing in PDK repair, but the bad/good news is that the number failures on out-of-warranty cars seem small enough to not make it a compelling business (yet).

Big Swole

Subscribed!!!



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Kainedogg

Fantastic write-up OP. I'm keeping this thread close.

Prairiedawg

Here are codes from a failure on the 991 thread. I told him to reach out to the OP. Maybe you can decode his failures.


https://rennlist.com/forums/991/1223...l#post17035226

PV997

Thanks, he sent me a PM but I'll post some thoughts here.

P17F1 and P17F2 are overtemp warnings on the PDK. The PDK has both a measured temp (from a temp sensor on the valve body) and a calculated temp (uses speed sensor data to determine if the clutches are slipping and therefore increasing fluid temp). Either one can throw these codes. Unfortunately I only have the 997.2 codes and P0731 and P0700 aren't in the 997.2 code list.

So there could be multiple potential causes that I can think of:

1. Low or burnt clutch fluid
2. The temp sensor could be faulty (known defect in early 997.2 PDKs)
3. A speed sensor could be faulty and making it seem like a clutch is slipping when it really isn't
4. One of the two clutch fluid pressure regulator solenoids could be failing and causing slipping
5. The clutch auxilliary fluid cooling circuit solenoid could be failing
6. A clutch itself could be failing and slipping (unlikely with low miles)
7. PDK fluid cooler has an obstruction or restriction in flow
8. The TCI is faulting and misreading sensors

First thing to check would be fluid obviously. After that there are simple things that can be checked with a multimeter such as the temp sensor and solenoid resistance. In order to narrow it down further a PIWIS clone can be used to read the sensors in real time and see if the values make sense. Things to look for would be low fluid pressure, erratic temp readings, erratic speed senor readings, etc. Upthread Mr. Hobbiest had a very similar situation where he speed sensor was going crazy (erratic) and the TCU interpreted it as clutch slipping and threw an overtemp fault.

Here's another interesting tidbit, Mr Hobbiest also had a P0730 code (similar to the 991's P0731 which isn't in my code list) which is a "rotational speed of input and output shaft fault". In other words, the TCU thinks the clutch is slipping because the speed sensors on either side of them don't agree. That would likely trip a calculated overtemp fault. Usually the faultd codes are grouped togther so those close in number are similar faults. Maybe they added a new one for this on the 991.

If anyone else has any thoughts please post them. Also if anyone has the 991.1 PDK errors code list it would be greatly appreciated!

tweej

Adding a data point to this thread.

My 2012 987.2 S PDK with the factory limited slip differential recently failed. Here is how it died (16minutes 30 seconds):
Car was at 49,500 miles with lots of track time. Air temp was 57F. Coolant was at 214F. I have the 3rd (center) radiator on the car.

I see these codes on OBDII. Not sure if the PIWIS has more/different ones.
P0700
P1731
P17D1

Currently looking at replacing with a remanufactured unit.

GTSpure

I really appreciate your research on PDK.
Very interesting and I wish all of us that we will continue to learn more and it will allow us to fix our PDK like any other part in the Porsche.
Cheers

GTSpure

Hi,

I'm sorry to hear and I hope to hear good news..

Regarding fault code P1731

See the following link:
https://www.2carpros.com/questions/pdk-gearbox
"I found solution for this case,
Porsche Panamera Uses ZF Transmission, for P1731, P1732, P1733, P1734 fault codes not required to replace gearbox (PDK) or transmission control unit, Just simply replace following part:
- Sensor Pack (Position Sensor with Speed and Temperature Sensors)
- Part #: 97031708500, Estimated Price is 500 USD.
But before any replacement, make sure your battery life is good, because Porsche is one of the most sensitive cars to over / under voltage situations. So much technology is packed into them, that bad or going battery can and does make funny things with totally unrelated systems.
Everything in the car is controlled by microprocessors and when the voltages get low you get weird signals that can be misinterpreted by the other processors.
If not worked, then try to replace with above sensor pack."

sub-zero

maybe someone have one its from the oil pump ?? please pm if you got one !