mskar

I'm still expecting my used PDK CU any day. In following the procedure from the alldatadiy documentation on CU replacement, I have to read the data from the old controller and then perform a "control unit replacement" in the PIWIS software. I see "control unit replacement" under almost every system on the car except for the PDK section. The entire PDK "Maintenance Repairs" page is empty, I do have the Programming options available on the "Coding Programming" page. If someone with a PDK has the time to hook a PIWIS to their car, could you send me a screenshot of what the PDK "Maintenance Repairs" contains on your car?

If I'm unable to read the old controller, I'm now alone in the wild. I cannot find a single reference to replacing a completely bricked controller without a functioning existing unit. Which begs the question, why would you be replacing the unit if it functioned?

hueyhoolihan

what's a jump box. is it some sort of extra battery? and if so, why would it be necessary to use it with a fresh battery?

when detecting electrical problems, i try to minimise the variables and potential complications until the problem shows that it can be resolved using the fewest extraneous devices as possible. then add them back on, one by one, until the problem returns.

t-design

A wild suggestion - we do have some history of PDK calibration problems with PIWIS-3, and then PIWIS-2 was successfully used after. Just something to keep in mind

matbreth

It seems to me that a need a strong additional power supply when you want to program an ECU with Piwis. Battery, event fully charged, is not enough.

mskar

Thanks Huey!

Jump-box, booster box, basically a heavy duty battery-device capable of jump starting a car. This one is made for industrial equipment so its pretty heavy duty.

The reason I'm using this is that on the PIWIS controller programming screen, there are multiple warnings about making sure you have a charged battery AND a min 40A charger hooked to the battery. The programming and calibration operates the solenoids and rods to calibrate min/max settings over a period of up to 30 mins, so I get why they want plenty of power. A voltage dip could at best slow down the operation and at worst, drop low enough to interrupt the computer, bricking it.

The only reason to suspect anything electrical, is the PIWIS "Battery Voltage Low" message. I have received this message since day one, even when the car was operating perfectly. I suspect the 3rd party PIWIS adapter is reduced capability over the factory one. I see other indications of "missing" functionality as well. I'd love to get confirmation on this from other PIWIS3 users however! Incorrect assumptions are a deep hole.

banksc01

What is the voltage on the jump box removed from the car? How does that compare to the voltage showing in PIWIS when it is connected? They should be similar, but the small load added when connected to the car may drop the voltage a bit. If there is a large disparity between loaded and unloaded, you have a different problem. If the voltage of the box doesn't meet what Porsche thinks is the minimal voltage, it will trigger the warning. I have ~13.8V on my supply when connected, and get no warning. I know a 12.4V battery will trigger the alarm, but I don't know what the limit is.

I don't see why the clone head would have any affect here. It is just a communication device, my understanding is that the voltage measurement is coming from the car.

mskar

Thanks for the info, I think you nailed it. The Booster only shows 12.4-12.5 when connected. I'm going to ask a couple of neighbors to help me push it to my driveway tonight and hook up an A/C charger, the booster seems to only juice the battery if below 12.4. Thanks for verifying your PIWIS reads correctly and that the message is likely valid. VERY helpful and evidence of my incorrect assumption. Thanks again!

mskar

Yesterday's update. New PDK CU arrived, swapped it and the car was able to start and run, but with no transmission control of course. PIWIS showed the computer mismatched to the car (I'll get codes, I was in a hurry and didn't take screen photos). The Maintenance options shows "replace control unit" with this unit, but not with the failed one (more evidence it is completely bricked). So, I have a computer, but no data off of the old computer to program the new one. I REALLY do not want to have to pay Porsche $2000 to put a new computer in my car, I have no doubt they will refuse to program a used computer and want to sell me a new one ($900) and then the little kids running around that shop will likely spend 4-5 hours trying to find a procedure for this because its not an oil change.

I manually edited the PDK CU VIN to match my vehicle and it got a bit further in PIWIS. Currently the primary code relates to the Engine Type being different. I don't want to keep going down this rabbit hole of manually changing values before seeing if anyone has been down this path before (even with a different system). So...

- Does anyone have any ideas as to how I can recreate the data that would have been read off of the old computer using the Maintenance|Controller Replacement|Read Data procedure? (all of this data was marked as "2900?" on my old controller and the "Maintenance" page in PIWIS was completely empty)
- Could Porsche engineers actually be THAT dim-witted that they would provide no way to replace a failed computer?
- Do I risk using the "Program Controller" functionality? I would think that function was for simply updating firmware.

I guess I'm going to see if I can locate the information recorded in the PDK CU from the other modules (DME, PDK selector, Gateway etc) and modify the PDK CU values to match, provided I can find those values. I don't have high hopes for this route, if the information were present in the other computers it would have been trivial for Porsche to put a "initialize computer" process into the Maintenance page that read all those values and programmed the new computer with the correct values.

I'll try to break away today and get some codes read and posted. Thanks!!! Marc

mskar

Today's update... DO NOT USE A PIWIS 3 "clone" TO PROGRAM A PDK COMPUTER

The replacement computer is now bricked after attempting to use the PIWIS 3 to program the unit. Same symptoms, no communication to diags and all values replaced by "? 29000". Will try a PIWIS 2, according to some other suggestions but I have a bad feeling about these computers. I suspect Porsche didn't bother with a ROM bootstrap loader. I have an EEPROM programmer, If I can locate the code, maybe I can force update it but somehow I doubt there is just a simple DIP EEPROM on board considering its post 1990's.

Docbentley

I hate to pay dealers for services also, but sometimes it is best to bite the bullet and save lots of gut lining and reduce stress and skinned body parts.

mskar

I'm going to try a PIWIS 2 as some have suggested then resign myself to getting it towed to the dealership. I have a client who builds industrial equipment and programs Siemens PLCs en masse. I was also thinking of popping the cover and seeing if there is a binary programming port on board (I did find the .bin file that the PIWIS3 is supposed to be writing).

I'm hesitant to break the tamper-proof seal, but I'm already of the opinion that Porsche is going to say "you need a controller" no matter, what and charge me $900+ for it and another $500 to program it so breaking the seal probably doesn't matter much.

mskar

Opinion request

If/when I tow this car to the dealership... play dumb or tell them the PDK got wiped out by a shop and ask them to program it? I've owned Porsches for 23 years now, never needed to use the dealer before other than the parts counter a few times. Specifically Checkered Flag in VB, VA

mskar

Well, two Thursdays ago, I had my Cayman flat-bedded up to my local Dealership, Checkered Flag Porsche in VB. I went full boyscout, told them exactly what happened at the track, gave them my research notes and asked them to reprogram both computers, and see if the vehicle data was still present. From past experiences with other dealers and shops, I was expecting pushback about "we'll do our own diagnostics" and we can't program a second-hand computer, etc. I was pleasantly surprised, they put me through to the service manager who is an HPDE instructor and we ended up chatting for about 20 minutes about Porsches, VIR, and performance upgrades. He told me "no problem", they'd take a look.

They were able to reprogram both computers, and performed a PDK clutch calibration, my Cayman is running perfectly now. This is EXACTLY the work I was trying to perform using my "PIWIS 3" when it failed miserably. The total cost was just under $600, which I thought was fair for a dealership repair, hell, the independent out at VIR charged me nearly $800 and made it worse.

I didn't have a chance to try the PIWIS II to see if it fared any better, and I don't want to risk wiping the programming off either of my PDK computers just to test it. Before track season, I may attempt to perform the "Replace PDK Controller" operation so I can swap in the replacement controller (Dealership left my factory issued unit in place), the "Read" function is now present, and executes on my original PDK controller, though I have absolutely NO IDEA *where* it is saving that data. I don't really trust the old controller as I still suspect the issue was due to an overheat, that is the only way I can see for a computer to just completely lose its programming:

P18B4 – Software Error
P1990 – Positive engine torque intervention not possible
P1991 – Engine torque intervention not possible

C152 – Communication PSM control unit (drive)
C150 – Communication DME control unit (drive)

5400 – Fault Sport Mode

8005 – Terminal S – (upper limit value exceeded)

P1552 – function monitoring: CU fault group a
P1629 – Fault manual transmission control module

Anyway, I seem to be the only person in the world who has experienced this particular issue so far. Hopefully this thread will prove valuable to someone in the future if this issue ever crops up again! Another factlet that might be useful, I forget the Option Code, but this car was one of the very earliest production 987.2's, the option code indicates that it was a Demo car, maybe a press car? The PDK controller was absolutely superseded during the 2009-2012 production, maybe there is something there. When I have a chance I'll grab the P/N and the Option code and append it to this thread. Again, for posterity at this point.

Happy to be back on the road! Thanks to everyone for their suggestions and help in resolving this issue!

Ubermensch

Very happy to hear you got it sorted. $600 seems like a great deal given the time and energy you were spending. This will certainly help someone in the future.

redlightrich

Thank you for keeping this thread interesting and informative. I am really happy for you that it is finally sorted

Be well

Rich