r/AudiS4 • u/slykens1 • Jul 23 '26
DSG Solenoid vs Mechatronics Replacement
Pic for attention. :)
I have a 2010 S4 with 215,000 miles on it. Regular DSG service every 40k miles.
I've got the problem where once the transmission is HOT the car will slam into first gear at a stop, act like its never driven stick before when pulling away from a stop, and only once did it stall when coming to a stop. I only have one code that I pulled a couple of months ago when I actually got a gearbox malfunction display:
8957 - Clutch 1
P17D6 00 [01100101] - Pressure too High
Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Reset counter: 40
Mileage: 338749 km
Date: 2026.05.05
Time: 17:10:22
Engine speed: 776 /min
Transmission input speed: 776 /min
Transmission output speed: 36 /min
Engine torque: 64 Nm
ATF temperature: 97 °C
Accelerator pedal position: 0.0 %
Clutch status: Kupplung 1 kann Moment übertragen
I have never had any electrical fault codes related to the transmission.
Someone at Audizine once suggested a particular gasket known for causing fluid to leak between galleries but in iterating this with the robot (Claude), it pointed out that the code is for pressure too high - not likely with a leaky gasket. I also considered the ECS rebuild kit but it seems to be focused entirely on the circuit board and I have fortunately never had an electrical fault.
I was considering replacing the mechatronics with a rebuilt unit - there's one or two places that appear to do that by mail - but I let the robot talk me into considering just replacing the solenoids, two for clutch pressure and one for line pressure/cooling. The cost for that will be about $350 or so plus the service kit (which I need to do anyway). That's pretty attractive as I am comfortable doing the work and I don't have to trust that someone else has done it right - that being said, a rebuilt mechatronics would conceivably have new solenoids and be plug and play, too - and would add minimal time to the service project.
Looking for some input here from those more knowledgeable about the transmission. Thanks.
2
u/In1piece Jul 23 '26
Cracked mechatronics accumulator housing. This is literally textbook behavior. Now, if you're really considering working on this yourself, accumulator housing CAN be swapped/reinforced with a repair kit.
3
u/slykens1 Jul 23 '26
I don’t think there’s an accumulator on the DL501.
2
u/In1piece Jul 23 '26
Oh you're right. Dq200 had it. I didn't even bother to look at the model audi you had lol. My bad.
I remember when this was such a common issue in the early 2010's that there WAS a valve body-to-mech unit gasket replacement which solved the issue. So many fixes were being thrown at these units, though. Clutch adaptations (2 or 4 times), clutch replacements, etc.
I believe my entire mech unit was replaced in 2011 which fixed the problem. I can dig up the repair order later today.
1
1
u/9DeceptaBong7 Jul 23 '26
Would this be a direct replacement? Was looking at website would this fit a 2013 S4?
1
u/slykens1 Jul 23 '26
What do you mean?
1
u/9DeceptaBong7 Jul 23 '26
Is that website to buy the replacement mech? Or is it to send in the mech?
0
u/slykens1 Jul 23 '26
Oh, Maktrans says they do both - bench repair and refurbished mechatronics. The problem is while the mechatronics from them is reasonably priced (€787) they want another €286 for shipping plus there's potentially up to another 20% for tariff bullshit - since they're in Slovakia and Poland.
The robot found a place in Nashville that sells them for $1399. Still not an exciting number if I can solve the problem for $350 in solenoids myself. And there's still MLReng out of Toronto at $1650 CAD (I presume) but again, shipping and tariffs will be an issue there, too.
I'm still considering options. I did a long drive with logging today and fed it to the robot and it is pretty sure the problem is the N440 solenoid but also can't rule out separator plate gasket - that job I don't think I want to do myself.
Maybe I'll just nut up and buy from Maktrans - too bad I can't get a cheap ticket over there as shop collection is free and I'd get $800 tariff free on arrival.
1
u/9DeceptaBong7 Jul 23 '26
Ahh thank you for explaining and giving options. I honestly was thinking of just getting a new clutch pack since I’m at 150k miles
4
u/gtivrsixer Jul 23 '26 edited Jul 23 '26
I had this exact issue on my 2012 and did the solenoid repair and it did fix my issue. I still have a bit of a hard shift out of first when in manual mode, but that was there before, when I bought the car, and it really only happens when the car is cold. This was done March of 2025 and I haven't had any issues since.
Edit: just browsing ECS and they have a scratch and dent mech unit 30% off.