Audi TT Power Loss, Bad Throttle Valve Alert

I dealt with a very similar issue on my 2018 Audi A5 last year. Having worked on several cars over the years, I have some experience with electronic throttle issues. The symptoms you describe match what I experienced, reduced power and constant check engine light. My car also went into limp mode, which is a safety feature that kicks in when the throttle body or accelerator pedal module has issues. After checking several components, my mechanic found the accelerator pedal module was defective, causing inconsistent throttle response delay. The repair involved replacing the entire pedal assembly with electronics, which cost 265 Euro including labor. The fix completely resolved the performance issues and restored normal fuel efficiency. The air intake and throttle response went back to normal immediately after the repair. Before suggesting more specific solutions, it would help to know: Are you experiencing any delayed throttle response? Does the issue occur more when the engine is cold or warm? Have you noticed any unusual sounds from the throttle area? Have you scanned for error codes?

Latest service at 116455 KM For those interested in diagnostics: The error codes from my scan tool showed P0122 and P2135, pointing directly to a throttle position sensor malfunction. The issue matched others describing failing throttle body problems in the B-cycle engines. The throttle sensor issues caused unreliable engine idling and put the car straight into limp mode. Air flow readings were all over the place according to live data. The throttle body complete assembly needed replacement, not just the sensor. Total repair cost was 520 Euro parts and labor. No issues since the fix 2 months ago.

Thanks for the detailed follow-up on your TT throttle body repair. The error codes P0122 and P2135 definitely confirm what I suspected with my similar throttle sensor issues. Your symptoms match what I dealt with, the erratic engine idling and limp mode activation are classic signs of a failing throttle position sensor. Interesting that your repair required the complete assembly replacement. In my case, the initial throttle sensor diagnosis also revealed inconsistent readings, but we managed to resolve it with just the position sensor unit rather than the full assembly. The labor costs were lower at 265 Euro versus your 520 Euro, though that makes sense given the more extensive work needed on your car. Good to hear the fix has held up for 2 months. After my repair, I noticed immediate improvements in throttle response and the check engine light never returned. These B-cycle engines seem particularly sensitive to throttle body issues, but once properly repaired, they run perfectly. The diagnostic process on your car seems spot-on, tracking the live data readings is crucial for confirming throttle position sensor problems versus other potential causes of reduced power.

Thanks everyone for the helpful feedback on my TT throttle issue. After comparing my experience with others, I can confirm for anyone searching that the full throttle body replacement was definitely the right call. The technician showed me how the throttle sensor readings were completely inconsistent, which explained the poor fuel efficiency and constant check engine warnings. For future reference: While my repair cost 520 Euro for the complete assembly, it seems some cases can be fixed with just the sensor replacement for less. The key is proper diagnosis with the right scan tool to confirm if its the throttle position sensor or the entire throttle body thats faulty. The air intake and throttle response are now perfect, and the car performs like new. No more limp mode or power issues since the fix. Im relieved I didnt try any temporary fixes and went straight for proper diagnosis and repair. Just documenting the final outcome here for others who might face similar issues with their TT in the future. Thanks again for all the guidance, it really helped me understand the problem better before heading to the shop.