Expert advice: Dsg & S-Tronic Mechatronic failures


Expert advice: Dsg & S-Tronic Mechatronic failures

Volkswagen Dsg gearbox Volkswagen Dsg gearbox Volkswagen dsg gearbox with mechatronics

If you are a VW or Audi owner then you are familiar with the two names DSG and S-Tronic.  Both these transmissions have made a name for themselves in the last 8 to maybe 10 years. They are super smooth and changes gears extremely fast. In fact so fast that some reckon they are faster than a very good driver in a manual gearbox vehicle.

But what are they exactly and are they really any  good?  Some say its an automatic and some say its manual.  Some even say its the best of both worlds.

Whats the difference?

Which is better? Dsg or S-Tronic?  Well the answer might surprise some. Neither one is better than the other. In fact, they are the same.  These gearboxes is used in different guises by both the Audi and Vw groups and some of their other partners.  Basically its only the names that changes for the different brands.

Both these transmissions are known for their smooth shifting and fast reaction times.  They are also called “thinking gearboxes” because they always seem to know what the driver intends to do.  In short, they do not differ that much if any.

What is a Dual clutch transmission?

A dual-clutch transmission (DCT), or Direct- shift transmission (DSG) (sometimes referred to as a twin-clutch transmission or doubleclutch transmission) is essentially a type of automated manual transmission in vehicles. They are closely related to a manual transmission and uses two separate clutches for odd and even gear sets. It combines the convenience of an automatic with the efficiency of a manual transmission.

Audi refers to these transmissions as S-Tronic but essentially they are the same.

How does it work?

The Dsg & S-Tronic gearboxes uses two clutches, but has no clutch pedal. Sophisticated electronics (mechatronics unit) and hydraulics control the clutches. In a dual clutch gearbox the clutches operate independently. One clutch controls the odd gears (first, third, fifth and reverse), while the other controls the even gears (second, fourth and sixth). Using this arrangement, gears can be changed without interrupting the power flow from the engine to the transmission.

Common problems.

Although these are great gearboxes, some of them can develop some problems. Overall they are very dependable but we have seen them more than once in our Vag Spec workshops where customers have been given the wrong advice and wrong diagnostics done on them.  Lets have a look at some common problems.

  • Incorrect solenoid operation in the computer and periodic errors during diagnostic. More than one sensor can get faulty, and getting the data from them will be impossible. Electronic components on the main board may get damaged, and errors can appear on the software program of the gear change control due to incorrect data.
  • Temperature sensor failure – either failing outright or failing out of specification. Incorrect data will cause the computer to do what it thinks is right based on the data it receives; hence, failure results. When this happens, certain gears stop working, either at a time or all at once. You may notice grinding or bad fuel economy.
  • The most common problem on the valve body is usually the appearance of gaps between the valve seat and the valve under normal wear. The presence of elements that are not part of the composition of the transmission fluid can lead to rapid wear. Failures in the mechatronic unit can also result due to a problem in the automatic transmission in general.

Until the problem is fixed, the mechatronic unit will continue to break down. Proper diagnostic and maintenance are very crucial.

What is the Mechatronic unit?

A mechatronic unit is the control centre of the gearbox. It is found in the gearbox where we have the direct-shift gear oil (DSG). Its task is to manage the torque converter and the clutch pad of the gearbox via the transmission fluid under specific pressure. It is capable of performing shift operations in a second. The gearbox’s control unit is in constant communication with the engine control unit, and this helps to determine the right time when changing gear.

Simply put, the mechatronic unit is a computerised control part of the dual-clutch system. This unique advanced dual-clutch automatic transmission is found in many cars, but mostly Audis and Volkswagens. The dual-clutch transmission consists of two sub gearboxes, each with its clutch, that work together to shift the gear.

The electronic control unit is made up of sensors and valves (actuators) in one single component with the main function of opening one clutch and closing the other at the right moment. This results in smooth shifting without any interruption of the tractive force. The unit processes the sensor signal, operates the valves, measures the RPMs, and slides of the hydraulic gear mechanism.

The mechatronic unit evaluates the selection of data. From the data, it recognises whether the gearbox needs to change from first to second gear, for example.

What happens when they fail?

The challenge with these highly advanced transmissions is that at some stage something is bound to go wrong.  When things do go south, you need expert advice.  These days its not just any mechanic that can work on your vehicle anymore.

But what are the warning signs?  Here’s the most common signs of a mechatronic unit starting to make trouble:

  • Clonking in gears
  • Selector warning lights
  • Inability to select gears
  • “PRNDS” lights flashing
  • Gearbox keeps selecting the neutral position

When this happens its best to stop driving and speak to your local technician first.  Its not all doom and gloom though. In days gone by it was only your local Audi and Vw dealership who could repair these sophisticated pieces of engineering. These days there are specialist repair centres who can do even a better job of repairing the transmission. In fact, dealerships these days will quote on replacement of the whole gearbox and maybe if you lucky only the mechatronics unit.

Vag Spec Centres have become well known through out South Africa as experts on all Vw group vehicles as well as BMW, Mercedes, Mini, SEAT, Porche and more. The group specialises in the diagnostic and repair services for DSG and STRONIC transmissions. They pride themselves in excellent and honest customer service and will go the extra mile to get you back on the road with expert advice, the latest equipment and years of experience between all their qualified technicians.

Visit our VagSpec Centre branches here for expert advice on all transmission related enquiries:

VagSpec Centre Zeerust

VagSpec Centre Menlyn

VagSpec Centre Cape Town

VagSpec Centre Klerksdorp

Make your booking today: BOOK NOW


84 Responses


    1. Hi Shan,
      It is difficult to say whats wrong from your short description. Theres the possibility of clutch failure or mechatronic problems. You are welcome to speak to our Qualified Technicians or bring your vehicle in to one of our branches in Menlyn, Randburg, Klerksdorp, Zeerust, Cape Town and soon George.
      Feel free to contact me on this nr: +27 81 373 3329.
      I will also send you an email with contact details.

    2. Hi Shan … Please can you send me you contact details.
      I have the same issue and I would like to know how you went about sorting it out.

      1. Hi. Jolene and Shan. I have the exact convulsion prorm from gearbox when engaging gear 1, 2 and sometimes 5. Maybe we need a what’sup group to share experiences and solutions on this.

  2. Hi please could u give me a price on a couch pack for my golf 7 gti 2014 2l I have the box out already getting some fult codes seems like it’s slipping on down shift and car starts reving out by itself

    1. Hi Tristan,
      Thank you for your comment and enquiry. I will send you an email to get contact info and discuss further.

      Kind regards
      Nelius van Eeden
      081 373 3329

    1. Good day Rose.
      Thank you for your enquiry. Please do note that we are a service and repair centre. Unfortunately we do not sell parts. Should you wish for us to quote you on the repair or replacement, you are welcome to contact me on 081 373 3329.

      Kind regards
      Nelius van Eeden

    2. Hi Rose,
      Apologies for the late reply. Should you still need assistance, you are welcome to contact me on 081 373 3329.

      Kind Regards

  3. My polo 8 DSG 2019 model switches on but won’t start , what could possibly be the problem?

    1. Hi Khosi,
      Thank you very much for your message. Its impossible to say/guess just by what you told us in your message. We will need more information. Feel free to contact me directly on 081 373 3329 and I can assist further.


    2. Hi Nelius,

      I have a Polo 6R GTI and it has a spanner flashing on the dash when in motion but the car still moves smoothly. This spanner appeared months after changing my mechatronic unit. When we diagnose the vehicle we get a “hydraulic pump” fault code.

      What does this mean ?

      1. Hi Sibusiso,
        We will have to scan the vehicle ourselves to determine the fault or at least have the fault code. You are welcome to contact me vie whatsapp and I will see how I can assist.

        081 373 3329

          1. Hi Craig,
            We cannot say whats wrong with the limited info supplied and no fault codes. If you are close to one of our branches, we can scan it for you. We have branches in Randburg, Menlyn, Klerksdorp, Zeerust, Capetown and George

            081 373 3329

  4. Hi my car is not starting, it’s shows me put car on N or P and after 1 hour is say gear box mulfunction

    1. Hi Peter,

      That sounds like a classical mechatronic problem. You will have to get the vehicle diagnosed to be sure though. If you are close to one of our VAGspec branches, feel free to contact me and I will arrange a diagnostic test for you.
      We have branches in Menlyn, Randburg, Klerksdorp, Zeerust, Capetown and soon George.

      081 373 3329

      1. Hi, I have the same problem like that of Sibusiso…Am driving Passat fsi 2014 model it has a spanner flashing on dashboard for almost a year now but it’s moving. What might be the problem?.

        1. Hi Peter
          You will have to get the vehicle scanned to see what the problem might be. That flashing spanner can mean a lot of things.

          081 373 3329

    1. Hi Peter,
      That a difficult one to answer. At the agents they are extremely expensive. It also depends on what vehicle and gearbox. Theres whet and dry clutch systems, 6 or 7 speed etc. Should you need more info you are welcome to contact us.


  5. Hi my car polo tsi 1.2 2014 model has the ESC light on power loss due to that.. Rev count does not go above 2000 rpms.

    Subsequently the EPC light also went on… I got it diagnosed and I’m told water has gone thru the sensors ( they dried them but the problem persists) I was the told the water went thru the wiring, to the throttle body and ECU… I’m not trusting the technicians as I’ve been incorrectly diagnosed and quoted twice prior..

  6. Hi
    On the dashboard of my Audi says gearbox malfunction but you can keep driving and i have been driving the car like that for 9 month with no gearbox problem , what can i do about the signal on the dashboard


    1. Good day Boogie,
      The error message(signal) can mean a lot of things. Obviously not very serious at the moment because the car still drives. I would suggest you get it to a workshop for a quick scan to see what the actual fault code is. Only then will you know how serious the problem really is.
      We have workshops in Randburg, Menlyn, Zeerust, Klerksdorp, Cape Town and soon George.

      You can contact me here if you need to make a booking for that quick scan
      Whatsapp us here:


  7. Hey
    On my polo gti the is a spanner flushing on my gears what could be the problem? The car drives nicely

    1. Hi Ringetani,
      A Flashing spanner means it is due for service. Its just a reminder and your car will drive as normal. You should however get it serviced at least once a year or every 15 000 km as per Vw requirements. Once the car is serviced, the flashing light will be reset by the Technician .
      You are welcome to contact me should you require a quote on the service.
      081 373 3329

  8. I have a problem with my Audi A3 2.0 manual transmission, the issue is that in the morning it has a hard start . Will you be able to help me with it please

    1. Hi there Vhutshilo,
      Sure we will be able to help. Please be on the lookout for an email from me.

      Nelius van Eeden
      081 373 3329

  9. I have a 2015 Golf GTI DSG, and I occasionally get the following error. “Error: workshop! Leave vehicle only when selector lever is in position P.” Error does not last long, and does not have any effect on the cars performance. I have done some research and have seen that this is a common problem and Volkswagen do have a work around. Do you guys perhaps have solution to this and over the service?

  10. My golf 7 2015 model..automatic transmission won’t move but it does start, then it displays an “error transmission”…

    1. Hi Nelisiwe,
      Thank you for the enquiry. This very much sounds like a mechatronic problem. Please check your email for more info.

      1. Hi once again ,am dione I have polo gti dsg ge show me engine light I don’t know what may I do

        1. You have to get it scanned by a reputable workshop. An engine light can literally mean a 1000 different things. Impossible to guess.

  11. Hi
    Got a 2013 Audi A3 1.4TFSI Sportback.
    It uses a 7 speed dual clutch S-Tronic gearbox (dry clutch). Mileage is approx 280, 000km and is still going strong. After a drive, there an “electric or hydraulic” like sound that runs for approximately 1 min after the car is turned off. Was told this is from the mechatronic and it’s an early indicator of an oncoming problem with the unit. Can one check the health of their mechatronic unit proactively? If so, what would be involved?


    1. Hi Josh,
      I am not to sure that you can take that as an early indicator. A diagnostic scan will reveal all errors stored by the system. Feel free to contact me directly if you need some help.

      081 373 3329

    1. Hallo King,
      Transmission error usaully means the mechatronic is faulty. However, we will need to do a diagnostic scan to make sure. Please check your email for my details.

  12. Good day,

    I have a Golf 2014- 2015 SUV Automatic that has a Gear error issue and An error message stating”Error stop and Start…It’s now stuck on Gear 2…When I start the car it takes 30mins to an Hour to select a gear…when it selects a gear it jumps up and just goes to Gear 2…Please help with a quotation for the fix….

    1. Hi Thapelo,
      My apology for the late reply. You can contact me on my nr below if you still need assistance.

      081 373 3329

  13. Hi Nelius
    My Audi A3 2014 is stuck on park gear with the P letter flashing,and it cannot start,also showing ESP light

    1. Good evening,
      This could be a couple of things. Please check your email for my reply. You can also contact me on the nr below

      081 373 3329

    1. Good evening Sphe,
      We can have a look for you. I will email you. Alternatively you can contact me directly for assistance.

      081 373 3329

      1. Good evening

        I have 2014 audi A5 V6 i have a problem with gear 1,3,5 and 7 only 2,4 and 6 are working,its an automatic,I’m based in Johannesburg.

        1. Hi Sindiso,
          This sounds like typical mechatronic failure symptoms. Please send me a whatsapp on my nr below. I have also sent an email with all my contact details.

          081 373 3329

  14. Good day.
    I have a 2012 Golf 6 GTI DSG, I can change all (P,R,S,D,N) but when its on drive it changes gears till gear 2 only.

    1. Hi Siya,
      Your vehicle will have to be diaganosed but those are commen signs of a mechatronic failure.

      1. Thanks Nelius
        I’m in Pretoria and I dont want to drive the car in this state, do you do call out diagnosis or I need to bring the car to the shop? and if its a mechatronic failure, roughly much does it cost to replace or fix it?

  15. Hello

    I am driving a VW polo TSI highline DSG, when I select D it does not move automatically without a bit of accelerator and when I am moving slowly maybe in a gravel road the ref count sometimes goes up and down even when I am not pressing the accelerator, however when I am driving on the road everything looks normal with no problem and the power still 100 percent fine, what might be the problem.

      1. Good Day,

        I have the same problem. When pulling away in 1 st gear it is very jerky also and over revs when changing to 2nd,3rd,4th etc gears, otherwise there is no problems, Please assist. 2016 Polo 1.2 tsi dsg


        1. Tiaan. I would love to assist. Please contact me on my nr provided below for assistence

          Regards Nelius
          081 373 3329

  16. Hi
    I have a golf hi gti 2011 model , it once had a timing chain problem, twas fixed , onlybto find that my car was decated as well,my catalic convertor was stolen, replaced with a minicat and and a new co2 bank 2, my car is hard starting, high oil consumption, smokingbwhen accelerating or de-accelarating, as well as a titling sound, engen hesitation on cold start, what might be the problem

    1. Dumi,
      This one is very difficult to start guessing. It can also be a combination of things. Best advise would be to have it scanned to get a starting point.
      You are welcome to contact me directly and we can discuss.

      068 249 4175

  17. Hi there
    I’ve a 2013 Polo GTI DSG 1.4TSI
    In the morning when I left for work, i drove for like 3kms and the spanner started flashing on the cluster. The vehicle then stopped moving even on D. I tried to engage R, D, S but just couldn’t move.
    What could possibly be wrong?

    1. Hi Khruz,

      It might very well be the start of mechatronic failure. BUt you will have to get it scanned by one of our workshops. Contact me directly to arrange and discuss.

      068 249 4175

  18. Hi Nelius

    I can’t select *S* mode on my dsg gearbox. I drive a Golf 6 tsi 2012 higline model. I took it for a diagnostic and was told it’s my mechatronic has failed however car drives perfectly fine and I get all gears from 1-7 with no issues. I’d appreciate a 2nd opinion and also what will be the charge for the diagnostic? Thanks

    1. Good day,
      I can take a guess but a diagnostic will be the right thing to do. Diagnostic fees at our branches differ. Please feel free to contact me directly to discuss options.

      068 249 4175

  19. I have a VW caravelle here in my workshop 9887 kms . vehicle was fine parked at the airport and on return wont start or come out of gear . cant communicate with ecu . engine ecu cant communicate with
    Mechatronics. Can these units be repaired here in SA.


  20. Hi. I have audi a3 2014 tfsi s tronic only engaging gears 2, 4 and reverse. Please advice what could be the problem and what steps to take. How will to repair.

    1. Hi Ntwampe,
      It’s really impossible to say how much it will be to repair your vehicle just from your description. You will need to have it scanned with proper diagnostic equipment. AFter that we will be able to quote correctly.

      Your are welcome to Whatsapp me for more advise. Also check your email for my response.

      081 373 3329

  21. Good morning

    I have a VW Polo Automatic. The car jerks when you shifting to drive and Reverse and also drive with D3 only does change to other gears.

    Scanned the car it tells about

    Replaced whole gearbox with a second hand but still says the exact errors.

    Could it be the Transmission control unit which went faulty?

    1. Hi Themba,
      These faults indicate a couple of sensor problems but also a solenoid problem. A full diagnostic is needed for us to be able to assist better. Ifyou are close to one of our branches its maybe a good idea to pop in and let us have a look for you.

      You are welcome to contact me on whatsapp if you wish

      081 373 3329

  22. Hi,

    I drive a 2019 Tiguan R-line DSG and I received a “Gear box in emergency mode” error on the cluster while driving. I then stopped the car, turned it off and on again a couple of minutes later.
    The error went away and the car is still drivable. What could be the issue in this case?

    1. Kamo,

      This might be the start off more serious problems. You will have to get it scanned to be sure. A foult code should be registered in the Ecu and then work from there.

      081 373 3329

  23. Hi
    I have a golf 4 with a faulty gearbox
    Everytime i take the car for gear repairs it leaves the machenic fine and after a few km gear 5 locks me out and im left with either gear 2 and 4 or 1 and 3..

    Is this fixable

    1. Hi Thabang,
      Its should be fixable depending on the amount of damage on the inside. Only way to know is to actually strip and access.

      081 373 3329

  24. Hi

    My audi, doesnt start, the battery is new and doesnt spark the gear gets stuck…

    Could this be the same megatronic components..


    1. Hi Jerry,
      Its unlikely that the problem is related. You will have to get it scanned. A car that does not start can have many other issues. Only way to know is to have a proper diagnostic done.

      081 373 3329

  25. Hello, I’m driving Vw golf 5 DSG, the car drive fine when is cool down, but after driving for 20 minutes or it starts doing rough shifts gear 1,2,3 and rough down shifts

    1. Hi Innocent,
      I would recommend you do a gearbox service and make sure you put the correct oil from Vw in the gearbox. If the problem persist, you should then have it checked out by a proffesional.


  26. Hi There,

    My polo gti dsg is only selecting 2 4 and 6 and there’s a spanner blinking on the dash in place of were the gear number is showing.

    Kindly assist, and advice what’s the next step to get this repaired.

    1. Shaneel,

      You will have to get it scanned and work from there. Let me know which of our branches is closest to you. You are welcome to whatsapp me for easier communication.

      081 373 3329

  27. Hi Nelius,

    My polo 1.9tdi has sump and clash plate issue, are you able to quote me on that?

  28. Hi, is there a difference between a JLU & KDM vw gearboxes. I am failing to understand if there are the same then why different acronyms? My gearbox died and I bought a second hand one but I could only get a JLU instead a KDM for my touran.

    1. Benedict,

      We will need more info to assist but there will be a software difference between the 2 boxes.

      You are welcome to contact me directly

      081 373 3329