A7 Rough Idle Points to Failing Throttle Sensor

I had a similar issue with my 2017 A6. The engine throttle response was terrible and fuel consumption went through the roof. The symptoms match exactly what you describe, unstable idle, poor throttle position response and starting problems. After trying to clean the air intake and throttle valve myself with limited success, I took it to a workshop. They diagnosed a faulty accelerator pedal module, which was causing incorrect throttle position readings. The repair cost me 205 Euro including parts and labor. The fix completely resolved the rough idle and high fuel consumption issues. The repair process took about 2 hours. Since the throttle system is electronically controlled, they needed specialized diagnostic equipment to properly calibrate the new module after installation. Could you share: Current mileage on your A7, Any check engine lights or error codes, Whether the issues started suddenly or developed gradually, If you notice the problems more during cold starts This information would help determine if your case is similar and whether you might be dealing with the same accelerator pedal module failure. As someone with some experience working on cars, I would suggest having it professionally diagnosed rather than attempting DIY fixes, since the engine throttle system is quite complex and requires proper calibration tools.

Last service was at 52000KM and problem started about 1300KM later. No check engine lights showing. The issue developed gradually over 2-3 weeks. After reading about similar cases, I did attempt basic throttle cleaning with a specialized cleaner spray, but it only helped temporarily. The rough idle returned after a few days and fuel efficiency remains poor. The poor throttle response seems worse during morning starts. The accelerator pedal module issue you mentioned makes sense given the symptoms. Did your fuel consumption return to normal immediately after the repair?

Yes, my fuel consumption improved dramatically right after the repair. The control valve and throttle body started working together properly once the accelerator pedal module was replaced, bringing consumption back to normal levels within the first tank of fuel. The temporary improvement you saw after cleaning suggests the throttle valve might be contributing to the issue, but the pattern of symptoms, especially the cold start problems and gradual onset, closely matches what I experienced with the faulty module. My repair cost ended up being worth every cent as the car throttle response became crisp again and the idle smoothed out completely. The air intake system started working as designed once the proper signals were being sent from the pedal. For reference, my issues started around 58000KM, so our situations are quite similar. The same accelerator module is used across the A6/A7 platform for those model years, so it could very well be the same component failing. Would suggest getting it checked soon, as continuing to drive with poor throttle response could potentially cause additional strain on related components.

The symptoms you describe with the accelerator pedal module match my situation perfectly. Thanks for sharing the repair details, good to know it was a relatively quick fix at 205 Euro. My mileage is at 53300KM now, and like your case, the engine throttle issues appeared well after the regular service interval. The fact that throttle cleaning only helped temporarily makes me think the module could indeed be the root cause, especially since the problems are worse during cold starts. Given how the unstable engine idle and poor throttle response mirror your experience, I will schedule a diagnostic check this week. No point risking additional wear on the car throttle system by waiting longer. The fuel consumption issue alone makes it worth fixing quickly. Will update the thread once I get it diagnosed and repaired in case others run into similar throttle valve problems with these models.