Guide to Repairing a PDK Transmission
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Pinkawa (07-31-2021)
#137
Three Wheelin'
Thread Starter
UPDATE: Here are the pressure sensor pinouts:
PDK Connector (A connector, closest to engine):
- Pressure sensor 1: A11
- Pressure sensor 2: A12
- 5 Volt supply: A13
- Pressure sensor 1: B30
- Pressure sensor 2: B31
- 5 Volt supply: B20
Measurements would be between the sensor pin and the 5V supply pin. The TCU connector is much easier to access as it's located inside the vehicle beneath the rear door. I don't know what the reading of a "good" sensor is but they shouldn't be open (>0.9 MOhms) or shorted (<2 Ohms) according the the Porsche T-shooting document. There are two so you can compare their measurements as a sanity check, since it's very unlikely both went bad.
Last edited by PV997; 05-25-2020 at 02:28 PM.
#139
Three Wheelin'
Thread Starter
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subaru335i (05-26-2020)
#141
Three Wheelin'
Thread Starter
Any transmission symptoms (e.g. slipping) prior to the codes being thrown?
#142
Update - Indy shop says he thinks the Piwis clone can datalog and will help when the car returns.
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subaru335i (05-27-2020)
#143
Latest VAL from dealership
Tried to get some info from dealer today about stored codes and the service adviser told me the code was 63334(whatever that means). Also commented that the temp sensor should be replaced.
Latest info from Dealership VAL report:
PDK Fault Codes
P17F0 - Transmission overtemper., stage 1 (exceeds limit value)
P17F1 - Transmission overtemper., stage 2 (exceeds limit value)
P17F2 - Transmission overtemper., stage 3 (exceeds limit value)
PSM Fault Codes
5400 - Fault Sport Mode (No fault symptom available)
PAS Fault Codes
8002 - Terminal 15 (exceeds limit value)
8003 - System disturbance (Signal implausible)
8021 - Wheel electronics, front left (below limit value)
8022 - Wheel electronics, front right (below limit value)
8023 - Wheel electronics, rear left (below limit value)
8024 - Wheel electronics, rear right (below limit value)
ECU Information Fault codes
C130 - Communication steering wheel electronics (comfort)(no signal)
Latest info from Dealership VAL report:
PDK Fault Codes
P17F0 - Transmission overtemper., stage 1 (exceeds limit value)
P17F1 - Transmission overtemper., stage 2 (exceeds limit value)
P17F2 - Transmission overtemper., stage 3 (exceeds limit value)
PSM Fault Codes
5400 - Fault Sport Mode (No fault symptom available)
PAS Fault Codes
8002 - Terminal 15 (exceeds limit value)
8003 - System disturbance (Signal implausible)
8021 - Wheel electronics, front left (below limit value)
8022 - Wheel electronics, front right (below limit value)
8023 - Wheel electronics, rear left (below limit value)
8024 - Wheel electronics, rear right (below limit value)
ECU Information Fault codes
C130 - Communication steering wheel electronics (comfort)(no signal)
Last edited by Mrhobbiest; 06-03-2020 at 11:11 PM. Reason: New Info
#144
Three Wheelin'
Thread Starter
There was a campaign on the temp sensors in the early PDKs due to intermittent faults. Did he have any evidence the sensor was bad or was he just suggesting it since it's a known issue?
#145
Yes, I am familiar with the campaign. The service flow-chart did not point definitively to the temp sensor as the problem and therefore the quoted $3500 fix was ruled out. If I crack this thing open to test and or change solenoids, I would assume that most would suggest changing the sensor ($35 kit?) right?
#146
Three Wheelin'
Thread Starter
Yes, I am familiar with the campaign. The service flow-chart did not point definitively to the temp sensor as the problem and therefore the quoted $3500 fix was ruled out. If I crack this thing open to test and or change solenoids, I would assume that most would suggest changing the sensor ($35 kit?) right?
#147
Rennlist Member
Sure, it's probably not a bad idea even if you aren't already in there. I may have said this already but the second attachment to the main post shows the R&R procedure from the campaign, it's not hard. No one in their right mind would pay a dealership $3500 to do this, I don't know how these service advisers sleep at night. It's a $40 part, a few hours worth of work, and then a PIWIS clone is needed for the refill. You can check its resistance at the TCU, the pinouts and resistance curve are in the post. If it's intermittent it might look fine though, FWIW.
Also, I keep reading threads where a PDK failure is indicated but it turns out to be completely unrelated like bad ignition coils or something. I'm not sure how one problem would relate to another but as these cars get more and more complex and rely on communication between modules, the gremlins they may bring increase. I find in my field, HVAC, that the technology moves faster than the ability and the resources and knowledge base moves to diagnose and troubleshoot things. Sometimes it takes that special tech to be able to think outside the box and determine the problem and solution, not the symptoms. Those guys are hard to find and are worth their weight in gold. Many techs, whether automotive or fill in the blank, just check boxes and if the answer isn't obvious or the computer doesn't tell them the solution, just shrug their shoulders and throw parts at it. It sounds to me like many times in this situation, throwing a part at it includes a $25,000 PDK.
#148
Three Wheelin'
Thread Starter
I would check the reported temperature cold. If the PIWIS can monitor the temperature in real time then checking cold is the first place to start. Then start and drive the car and watch the temperature. If shows implausibly high temps right away, it's likely the sensor. My 911 takes 10 minutes of driving or about 6 miles to warm the oil temp to 175. That's with combustion processes going on. I would think a cold trans would take a while, with most heat coming from the trans cooler until it got up to temp and the heat flows the other direction. If the temp rises too fast then also likely the sensor. Resistance typically goes up with temperature and the values of a bad sensor can increase too quickly indicating an invalid temp while the actual temperature is perfectly fine.
This could easily be done by a dealer with a PIWIS (I've got a PIWIS clone and it's simple) but it is virtually impossible to find one willing to do it. Instead they'll write-up a $3500 shot-in-the-dark repair that likely will do nothing to actually fix it. They claim their hands are tied by PCNA and they can't do these tests but somehow their hands aren't tied from throwing thousands of dollars in parts and labor *****-nilly at the problem. Anyone taking their car to a dealership for anything other than warranty work or simple maintenance really should reconsider.
A PIWIS 2 clone is only $400 and several of us have them and confirmed their capabilities. That's less that some dealers charge for an oil change.
Last edited by PV997; 05-31-2020 at 12:30 PM.
#149
Three Wheelin'
Thread Starter
Noticed yesterday that a Chinese aftermarket company is now selling PDK valve body solenoid kits and remanufactured clutches for ~$230 and ~$800 respectively. They claim both are in stock and I've added links to the main post. Hopefully we'll see more of this type of stuff, here's a photo of the solenoid kit. The different-looking solenoid at the lower right has what I think is a fail-safe pressure regulator and I've been unable to identify the part number. Nice to have a potential source for these.
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#150
Pro
Great thread! Thanks for contributions to everyone, good to know.
Has anyone tried 991 PDK in 997.2? Specifically 2012-2015 models which should be compatible. Does anyone know if final drives compatible for C4 variants and are sensors the same or is there some changes that would need to be implemented ?
Additionally has anyone tried converting their AWD / C4 to C2 ?
Has anyone tried 991 PDK in 997.2? Specifically 2012-2015 models which should be compatible. Does anyone know if final drives compatible for C4 variants and are sensors the same or is there some changes that would need to be implemented ?
Additionally has anyone tried converting their AWD / C4 to C2 ?