Audi S-Tronic mechatronic fault

Audi S-Tronic transmission fault

Seven speed longitudinal Direct Shift Gearbox (DL501).

This S-Tronic transmission unit fitted to high performance Audi’s, with the 0B5 DL501 Direct Shift Gearbox (DSG), is a very common failing mechatronic control unit.

Internal component breakdown of the S-Tronic mechatronic control unit will cause a multitude of symptoms on the vehicle beginning with the illumination of the EPC (Electronic Power Control) and PRNDS warning lights. The running symptoms that a fault within this mechatronics unit will cause include limp home mode, harsh gear change and erratic gear selection. As the S-Tronic/0B5 gearbox mechatronics failure advances, these symptoms progress further into critical transmission failure: sticking in gear, deactivation of half of the gears, no reverse or gears above first.

When diagnosing the failure using scan tools you will find a myriad of fault codes relating to electrical valve faults, implausible signals and selectors not being regulated. All of which may clear but will return straight away or after a very short drive/attempt to drive.


Typically, when dealing with these Audi S-Tronic gearbox problems, main dealerships and specialists will seek to purchase an expensive replacement or repair kit direct from the manufacturer, which will also incur coding fees. The glaring problem with this method is that the manufacturer of this mechatronic control unit has not yet resolved the root cause of failure at factory level, meaning that all replacements and repair kit components still have the underlying defects that will cause malfunction, usually outside the short one-year manufacturer warranty.


We offer an enhanced remedy to get you back on the road: a fully re-engineered solution for all S-Tronic/0B5 mechatronic control units. Replacing common failing components with our own re-engineered versions, our mechatronic repair will outlast and outperform any original or replacement OEM part, so much so that we will provide an unlimited mile Lifetime Warranty for peace of mind. All of this within 2-3 working days


Common Failure symptoms:

  • No reverse gear
  • No gears above 1st
  • Gears sticking
  • No gears at all
  • Limp home mode
  • Harsh gear change
  • Jerking / behaving erratically


Common fault codes:

  • P0726 – RPM signal of engine control unit (implausible signal)
  • P173C – Valve 1 in sub-gearbox 1 (electrical fault)
  • P173F – Valve 2 in sub-gearbox 1 (electrical fault)
  • P1740 – Clutch temperature monitoring,
  • P174A – Valve 3 in sub-gearbox 1 (electrical fault)
  • P174B – Valve 4 in sub-gearbox 1 (electrical fault)
  • P174C – Valve 1 in sub-gearbox 2 (electrical fault)
  • P174C – Valve 2 in sub-gearbox 2 (electrical fault)
  • P174E – Valve 3 in sub-gearbox 2 (electrical fault)
  • P174F – Valve 4 in sub-gearbox 2 (electrical fault)
  • P176A – Gear actuator/selector 1 (not adjustable)
  • P176A – Selector 1 cannot be regulated
  • P176B – Gear actuator/selector 2 (not adjustable)
  • P176B - Selector 2 cannot be regulated
  • P179C – Main pressure valve (electrical fault)
  • P179D – Cooling oil valve (electrical fault)
  • P17D4 – Valve 3 in sub-gearbox 1 (mechanical malfunction)
  • P17D8 – Torque limitation due to clutch temperature
  • P17E0 – Gear actuator 1 mechanical error
  • P17E0 – Gear actuator/selector 1 (mechanical error)


Affected Vehicles:

  • Audi A4 (B8) 2008-2013
  • Audi A5 2008-2014
  • Audi A6 (C7) 2011-2014
  • Audi A7 (4G8) 2010-2014
  • Audi Q5 2008-2012
  • Audi RS5 2010-2015
  • Audi S4 (B8) 2009-2012
  • Audi S5 (B8) 2009-2017


Common failing part numbers:

  • 0B5 927 256 B
  • 0B5 927 156 D
  • 0B5 927 156 E
  • 0B5 927 256 F
  • 0B5 927 256 D
  • 0B5 927 165 J


Test and rebuild:

Each S-Tronic mechatronic control unit is comprehensively tested on our bespoke Hardware In-the-Loop testing rigs under real-world loads and driving conditions both before and after the rebuild to ensure that the rebuilt unit will meet, even exceed, manufacturer specifications. Using only our re-engineered versions of OEM components every rebuilt 0B5 mechatronic unit will outlast the vehicle it is fitted back into.



All programming information is retained during test and rebuild, once the S-Tronic/0B5 mechatronic is re-installed there will be no need for a costly programming trip to the main dealership.



Our strict quality control: encompassing testing, components and workmanship will ensure only the highest level of work is carried out to meet our lifetime warranty standards. Due to our extremely high standards we work very closely with dealerships and specialists, offering a better solution to replacement.



Lifetime unlimited mileage*


How do I get my unit rebuilt?

To pay for the rebuild select your vehicle and part number above and then click: Get yours rebuilt

Print the payment/booking confirmation email.

Package the Audi S-Tronic mechatronic inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).

Send us your package by tracked courier (the shipping instructions are on the confirmation email).

Once received we will test, rebuild and return your S-Tronic mechatronic with an unlimited mileage lifetime warranty. (if your unit turns out not to be faulty then we will refund your payment less a small testing fee and return shipping)


What if I don’t want to pay up front?

This is not a problem, if you prefer this option then follow the following steps:

Fill in and submit this test form.

Print the booking confirmation email.

Package the S-Tronic/0B5 mechatronic inside a sturdy box with plenty of packaging material (make sure you include your confirmation email in the box).

Send us your package by tracked courier (the shipping instructions are on the confirmation email).

Once received, we will test your Audi mechatronic and call you to advise on the outcome of testing, if your unit is faulty and you choose to go ahead with the rebuild then we will take payment over the phone using a debit/credit card.

We will then rebuild your transmission ECU / S-Tronic unit and return it to you with an unlimited mileage warranty.

If you require further information regarding this Audi S-Tronic mechatronic repair then please contact us.

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Comments on "Audi S-Tronic mechatronic fault"
Luis Moreno says: 24/7/2019 9:21:04 PM
My car is not listed. ? It's a A3 8v 2015. Transmission malfunction: you can continue driving. Dealer says it's a mechatronic failure, even though it's just a 4 and a half years old car. I live in the Dominican Republic ny the way. Any inputs?
ECU Admin says: 25/7/2019 9:26:23 AM
Hi Luis, it sounds as though you may have a faulty DSG-6 mechatronics unit, see this page for the DSG-6:
Yuichirou Taguchi says: 13/7/2019 2:24:30 PM
Hello. I have A6 transmission trouble. VIN WAUZZZ4G7CN093886 trouble code P174B00. P176B00.P17D800.P17D400.P17D600 P17D700. Can you repair this mechatronic?
ECU Admin says: 15/7/2019 10:50:52 AM
Hi Yuichirou, we have seen some of those fault codes before on faulty mechatronic units, we would need to fully test your mechatrinic to for sure if it is faulty, to see full price and shipping information then select your vehicle and mechatronics part number in the description above.
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