Audi TT Transmission Chaos: Electronics Gone Haywire

Had similar transmission issues with a 2012 Audi A5 2.0T. The gear selector problems and instrument panel failures pointed to a faulty transmission control module. The digital display showing incorrect gear positions is a classic sign of control unit malfunction. The grinding and rough shifts happen because the control unit fails to properly communicate with the transmission sensors. This creates incorrect shift timing and pressure control. When the control module starts failing, it typically affects both the mechanical operation and electronic displays simultaneously. The transmission control unit needed complete replacement. This was classified as a major repair since the unit requires specific programming and adaptation to work with the car systems. The sensor problem affected multiple systems including shift solenoids and speed sensors. While waiting for parts, the transmission went into limp mode as a safety measure. Would strongly recommend getting this diagnosed at a shop with Audi-specific diagnostic equipment, as generic scanners often miss the underlying control unit communication issues. This is not something that improves with time, the symptoms typically worsen and can eventually prevent the car from shifting altogether. The car dashboard warnings should be taken seriously as they indicate internal electronic communication failures.

Thanks for sharing your experience. My issue turned out exactly as you described, a failing transmission control module causing havoc with the gear indicator and shift operations. Just curious, do you recall the total repair cost for your control unit replacement? My Audi TT repair bill was quite steep due to the specialized programming needed for the new module. After the fix, have you noticed any other issues with the digital display or gear shift operation? The instrument panel readouts on mine have been perfect since the repair, but sometimes I still feel a slight hesitation when shifting from 2nd to 3rd.

Just wanted to update that the gear shift indicator display issue was completely resolved after replacing the control unit. The total repair came to 1000 Euro for fixing the affected control unit, including the specialized programming and testing. The electronic display and transmission have worked flawlessly for over 40000km now with no hesitation between gears. The car dashboard readouts remain crystal clear and accurate, showing correct gear positions at all times. This repair solved all the sensor problems I was experiencing. Your slight 2nd to 3rd gear hesitation might need a small transmission adjustment, worth mentioning during your next service. The investment in fixing the control unit definitely proved worthwhile since proper shift knob response and accurate gear position display are crucial for safe operation. My advice would be to monitor that hesitation, but otherwise you can feel confident the main electronic issues are resolved.

Thanks everyone for the helpful insights. I finally got everything sorted out with my TT. After taking it to a specialized Audi shop, they confirmed the faulty transmission control module diagnosis. The repair took 3 days since they had to order and program the new unit. Total cost came to 1200 Euro including labor and programming. The electronic display is now working perfectly and the gear selector feels solid again. Such a relief to see accurate gear positions on the car dashboard. The grinding noise is completely gone and shifts are smooth again. Just that small hesitation between 2nd and 3rd that I mentioned earlier. The mechanic adjusted the transmission pressure but said to monitor it and come back if it persists. Definitely worth fixing properly rather than letting it get worse. Good to hear others had similar experiences and successful repairs. Will report back if that slight hesitation doesnt clear up after a few more weeks of driving.