Toyota Auris MMT slipping to neutral and cant change gears

[colderminute]

So I've been having some issues with my toyota auris 08' MMT. After a few times of the car slipping off into neutral and not being able to change gears at some point it just completely stops fixing itself. Had a mechanic change a few parts and a week later same thing happened and im waiting to tow it back there soon. I read some older posts on here about this issue and it seems to have occured quite a few times to people with the same car. I was wondering if anyone who had this issue fixed is still on here to tell me on what they did. I get that MMT's apparently are just not worth it but wondering if anyone already found the fix to this issue. Saw somewhere that replacing the ECU works (not sure on the costs there)? Not from Uk so wont be able to take it to a toyota manufacturer.

[solero]

I am not an MMT owner or mechanic, but if you think about it logically. MMT replaces a foot on a clutch with an actuating motor, and ECU to detect the clutch biting/release point.
Clutches do still wear, and motors can wear carbon brushes, and switches/sensors can fail. 

Whenever the clutch or motor of the MMT system is replaced, the ECU needs to learn the new clutch biting point. This learning procedure is done via a utility in the toyota techstream software. Otherwise you may still have rough gear changes, or the "ECU trying to fix itself" (which it rarely does). ECUs very rarely fail, but moving parts are more likely culprits.

So you need to find a mechanic who can not only diagnose and fix the faulty part, but is also acquainted with the techstream MMT learning/calibration procedure. 

MMT is old technology, replaced by CVT and eCVT,. MMT repairs ate not in great demand, and  its not really worth an independent mechanic investing time/money on acquiring this old hat skill and toolset for a one off customer. So thats the challenge you are facing. 

I would not waste any time/money on a mechanic who at the very least is not equipped with the toyota techstream software (not some future dated "do-it-all" obd tool) Otherwise its just pot luck with the parts cannon.

Good luck with the search and repair.

[Sunny7]

I had mine repaired 3 times! The last repair was the best and the transmission has been fine since 2018...I found a gem of a mechanic, trained by Toyota! The previous 2 repairs were done by the Toyota dealership and IMO substandard! (And outrageously expensive!)