S-tronic Transmission Error Code - Can't find any info on it

[Gustaf]

Hi All,
I just bought a 2011 with only 48k miles on it with a known transmission issue. The guy I bought it from put in the new circuit boards (from Audi), filters, and fluid and nothing else but that didn't resolve his issue. For giggles, I cleared the codes and tried to run adaptation but that failed. The only code I get is 9707 - Sensor for Gear Actuator 1. When I google that, I get absolutely no results. Is this car a unicorn from an error code standpoint? Has anyone else run into this error? With all the issues these units have, I figured someone would have seen this before.
At this point I have removed the mechatronic and nothing looks out of sorts. I have checked resistance on each of the solenoids and they all check out OK. Any thoughts?
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[Gustaf]

No one has any thoughts? No DSG experts in house?

[Nillious]

I believe the code is P17E0 – Gear Actuator 1 Mechanical malfunction

[Nillious]

Lots of info here on the mech unit and solenoids

https://forums.audirevolution.net/t/...ussion/16069/2

[Smac770]

The more relevant code is the P17E0 than the 9707. 9707 is a DFCC, it just represents the involved component. It's not actually the error code, which is the "mechanical malfunction". The P17E0 better represents the error state.

And that's what you have out there, P17E0 through P17E3 for mechanical malfunction of gear actuator sensor 1 through 4.

"new circuit boards", specifically which circuit boards? There's three different ones, and the sensor of concern is on a specific one.

You should look at Audi SSP 429 (google search) pages 36 through 41, most specifically pages 40 and 41. Page 36 shows the overview with the valve body in gray in the middle, with the travel sensors 1 through 4 to the left. You see the hooks sticking out left from the hydraulic pistons. These are what the shift forks are latched to and what the solenoid valves move to actuate the shift forks. This is broken out on 38-39. And on 40-41, it demonstrates the hall sensors that are the "sensor for gear actuator", and their interaction with the magnets on the shift forks. This is how the TCM confirms the mechanical gearing is correctly positioned for the active intention.

This therefore is what I assume that P code means, the TCM is activating the solenoid and not seeing the correct position or the expected movement per the feedback from the travel sensor. Is the issue with the hydraulic solenoid, with the hydraulic piston, with the magnets, with the hall sensor? A break in any of that would not be known except through the failure of the expected reading from the travel sensor. Unless the solenoid was electrically defective, then the supply circuit to the solenoid would probably be aware and you'd get a different P code (one of the P173x or P174x codes). I don't know what different data would invoke the P176x codes, "gear selector cannot be regulated". I assume that would be "I've got no electrical error with control, and no mechanical error with travel reading, but the value won't stay in place".

http://wiki.ross-tech.com/wiki/index...rbox_(DSG/0B5)
Here, we see there was a software fix for the P17E1 (for the travel sensor for the 1st<>3rd fork for the clutch 1) - https://static.nhtsa.gov/odi/tsbs/20...52520-6657.pdf

But you probably need to try and find a technical document detailing the specific trigger criteria for the P17Ex codes for the DL501-7Q (type 0B5), and then review measuring values comparing those related to travel sensor 1 (for gear selector 2nd-Rev for clutch 2) vs those for travel sensors 2,3,4. Could be the fork isn't even latched to the hydraulic piston correctly.

But something about this area is what your P code is directing towards.

[Gustaf]

Thanks smac770 for the detailed reply! I have reviewed the SSP. With respect to the solenoids, while I did not replace the shift solenoids, I did check them via my meter and they all measured to spec. Honestly, if I could find good OE Borgwarner shifter solenoids, I would have replaced them just to rule that out and avoid future problems. I did replace the the pressure regulation, cooling, and main pressure solenoids since I could find those.
With respect to which circuit boards were replaced, it was the 2 that connect to all of the solenoids. If the 3rd circuit board you are referring to is the one with the hall sensors that is mounted to the TCM, I cannot find that as a separate replaceable part and from what the SSP states it is not seperable. If it was, I certainly would have replaced it. Are you aware of that being replaceable?
At this point, I'll be removing the mech again and taking another look at things. I may remove the TCU and send it off for inspection/refurb as I suspect that it may be the hall sensor that is bad but I will try to determine that.
Let me know if anyone has any other thoughts or a way to check those hall sensors.

[Gustaf]

Hey all,
Just wanted to provide an update. I ended up sending the whole mech unit off to a firm that was recommended and tests 0B5 mech units. Came back with a clean bill of health but I was still getting the same error code after installing. After consulting with the guys at Maktrans in Poland, they immediately said that the clutches were bad. Hearing that many folks have had clutches go bad, I dove into remove the transmission this past weekend (quite the project) and have removed the and disassembled the clutch basket. Sure enough, my K2 clutches (inner) were completely cooked and discolored. In the process now of rebuilding the clutch basket with new friction and steel plates and will likely reinstall of the trans this weekend.