SQ5 Power Loss & Check Engine: Throttle Body Issues

As someone with some repair experience, I dealt with a similar issue on my 2012 S4. The symptoms were nearly identical, sluggish acceleration, check engine light, and noticeable throttle response delay. After diagnostic testing, the problem was traced to a faulty accelerator pedal module. The electronics inside had degraded, causing inconsistent signals to the throttle body and affecting the air flow through the air intake system. The repair took about 2 hours and cost 265 Euro including parts and labor. The car runs perfectly now with smooth acceleration and no more check engine warnings. What I learned: These symptoms can stem from multiple sources, but the accelerator pedal module is a common failure point in these engines. The repair shop confirmed they see this issue regularly on similar models. To better assist, could you share: Any diagnostic codes if scanned? Does the issue occur more frequently when the engine is cold or warm? Have you noticed any changes in fuel consumption? Are there any other warning lights besides the check engine light? Does the problem happen gradually or suddenly? This information would help determine if your issue matches what I experienced or if it might be something else.

Just did my latest service at 137783KM and wanted to add, getting codes P2015 and P0638. The issue happens more when engine idling and cold starts. Fuel consumption increased by about 15%. No other warning lights besides check engine. Problem started gradually over the last 2 weeks and is now constant. The air flow problems seem worse in the morning, with rough idling for about 5 minutes. After that, the throttle response delay becomes the main issue. Interesting point about the accelerator pedal module, the symptoms match exactly what I am experiencing.

Thanks for the additional details. Those specific codes actually point to a different issue than what I initially experienced with my S4. P2015 and P0638 typically indicate intake manifold runner control problems and throttle control issues, respectively. Looking back at my repair history, I had similar symptoms later on at around 145000KM, but it turned out to be the intake manifold flap motor failing rather than the accelerator pedal module. The rough engine idling and increased fuel consumption match exactly what happened with mine. The repair involved replacing the intake manifold unit complete with new flaps and motor, cost was higher at around 850 Euro but solved all issues including: Poor air flow management, Rough cold starts, Increased fuel consumption, Throttle response delays The repair took about 4 hours and also included cleaning the air intake system. Engine performance returned to normal immediately after, with fuel efficiency back to standard levels within the next tank. Based on your codes and symptoms matching my second experience so closely, I would recommend having the intake manifold system checked first rather than focusing on the accelerator pedal module as previously suggested.

Based on this diagnostic process and the matching symptoms, I appreciate everyone's input. Given my codes (P2015 and P0638) plus the timing of symptoms, especially the air flow issues during cold starts and constant throttle response problems, I am now confident the intake manifold system needs attention rather than the accelerator pedal module. Will book the repair focusing on the intake manifold flap motor and complete system inspection. The 850 Euro cost seems reasonable considering the comprehensive fix it provides. The 4-hour repair timeline works well for my schedule too. Most importantly, knowing this should resolve my engine idling issues and restore proper fuel efficiency makes it worth addressing now before it causes more problems. Will update once the repair is complete to confirm if it solved all the symptoms as expected. Thanks again for the detailed diagnostic help. Having clear direction on the likely cause saves time and helps avoid unnecessary parts replacement.