If you encountered the dreaded TRANSMISSION FAULT error on your cluster while you drive, or if starting up, and notice that the car does not go into gear, acts like it is in neutral. Only way to clear is sometimes to turn off and back on, and often, to clear using diagnostic package. But error will never go away fully.
Once you scan the errors when 'Transmission fault' is present, you see shift rod 1 or shift rod 2, or shift rod xxx implausible signal messages.

I know how frustrating this error is. Some dealers have been advising folks to replace PDK. That is a 20k price tag job.
If you have these errors, you can repair it all on your own, at a price of about $1200 (parts cost plus day of your time while babying your car, and drinking a bit while doing so).

Before you start, you must know you have to recalibrate the PDK. This means, YOU MUST HAVE ACCESS TO PIWIS2 diagnostic tool. Same one dealers use. If you install new sensors, you will most likely be able to start and drive the car, BUT sometime soon, you will go into limp mode and card will be stranded. So before you start, make sure you have the parts, and the PIWIS2 tool (or have scheduled tow to shop that will recalibrate for you - that is a price tag on its own too).

TOOLS:
Not bothering with each tool specifically, but you will need ratchets, 3/8, torque wrench 1/4", E-torx, torx, thin flat screwdrivers for prying, regular sockets (18mm, 16mm, 13mm, 10mm), etc. Bottle jack, magnetic level to ensure bottom of car is level when you raise off ground (unless you have a lift/hoist).
You also MUST HAVE PIWIS2 setup.

PARTS:
- Replacement transmission pan kit (pan, filter, filter seal, pan gasket, gasket spacers, pan bolts, drain plug installed into new pan)
- Shift rod sensors - 970 317 085 30. NOTE: MAKE SURE TO USE YOUR CAR VIN WHEN ORDERING TO ENSURE FIT
- transmission harness - 970 317 615 30. NOTE: MAKE SURE TO USE YOUR CAR VIN WHEN ORDERING TO ENSURE FIT
- Pentosine FFL3 trans fluid (at least 10 quarts for V8 AWD)


Now, onto the process. Make sure you review every image (step). Read and understand what is going on. Only after that, get things going. It is a long process, although not too difficult.
BEFORE YOU START, CHARGE YOUR CAR BATTERY FULLY - you will need the charge during calibration.
After the replacement, YOU MUST RECALIBRATE THE PDK.
To do that you connect PIWIS2, scan the system (keep pressing F12 without highlighting any subsystems). Eventually you will get to the screen that will show subsystems that your car has, then you locate PDK, then see image 28 to help guide you through the rest of the process. The process is not as obvious as you would want. There are few times where you have to turn car off then back on. There is a timer that shows you how long you must wait, then tells you to turn car off/on. If your battery on the fob is near dead, you may turn key and nothing will happen, keep that in mind. Best to have good fob battery before you start too.

Well, here we go, follow steps from 1 to 28. Hope this helps you out. Good luck.































HIGH LEVEL PDK CALIBRATION STEPS

 

Wow! Another amazing write up by Dr. Ciaka! Hope to never have to do but feel empowered with this knowledge nonetheless! As always, thank you!

 

Good to hear. Once you know steps, it is easy. Dont give your hard earned $ to dealers who will skin you alive.

 

Great write up buddy!

 

Another excellent write up to add to the collection!

 

In latest update, error has not come back since. Issue is gone and fix worked. Excellent.

 

It has been a year or more since this replacement. Errors never returned. It was definitely the shift rod sensor failure. Replace sensors, CALIBRATE PDK to resolve this.
Again, failure symptom was transmission fault error on intrument, can would not engage into a gear (R or D), would do that randomly. Usually when left alone for few hours, it would correct itself for a while. I believe the errors in PDK diags were P1733 or P1734, dont remember exactly, but it could be anything from P1731 through P1737 I believe.

Updating to let y'all know, the job fixed it at a fraction of dealer price, BUT YOU MUST RECALIBRATE PDK after the job. Good day.

 

Hello, do you know what the real problem is with this part ref (970 317 08500).
the selection fork allows to have the alignment of the sprockets, on this part in question there are 4 sensors.
It would seem from what I could understand that inside these sensors there is a coil.
Could it be that it's the coils inside these sensors that eventually fail after years, and no longer give the correct eddy current to allow alignment?

 

My indy replaced sensor and harness and test drove for a half hour or so after replacing and found no issues. Is it POSSIBLE that it may not need recalibration? and if I’m willing to risk being towed to dealer later for recalibration would that be ok?! Thanks

 

While possible, if you get errors, you nay get stranded. Then you'll have to recall.

I have the piwis, and others chimed it after replace and no recal, they got stranded. Imo, calibration is the way to go. If ypu don't have access, I guess you'll take a chance. Hope it works for you though.

 

Amazing, Dr.Ciaka. That is $10K easily @ Porsche dealer. Thank you for posting. Full Tranny service is $2.2K with 20% discount already from Porsche. I just did it DIY with your procedure.
Many Thanks.

 

Glad it helps my friend.

 

Wanted to take a moment to thank you so much Ciaka for this DIY! When this happend to me in the begining of this month - Aug '23 - it enabled me to diagnose and source the right parts from a reputable connect. Additionally, the DIY it allowed me to show my local mech (who has a PIWIS2) the step-by-step work I needed done and have him tackle it for me. He just charged my the labor for the hours it took for him to do it (~5) and his hourly rate is resonable. Many thanks brother for saving me time and money. Two things everyone could benefit from more of.

Salute!

 

That's awesome. Great to hear and glad it helped too.

 

Hello,

My indy shop just performed this and stated that the harness didn't need to be replaced. Now, the panny won't relearn reverse or neutral on the calibration. Thoughts and input is appreciated.