BMW M3 Throttle Issues: Limp Mode & Idle Problems

Hey there! I had nearly identical issues with my 2003 BMW M5 last year. The symptoms you're describing match exactly what I experienced, unresponsive throttle, erratic idle, and limp mode. Initially thought it was the throttle body, but turned out to be a faulty accelerator pedal module. The garage diagnosed it by checking the pedal position sensor readings, which were inconsistent. They replaced the entire pedal module assembly and recalibrated the system. It was a serious issue since the car was basically undriveable, but the fix itself wasn't too complex. The repair took about two hours, and the car's been running perfectly since then. Just make sure you go to a shop that specializes in BMW electronics, as they need specific diagnostic tools to properly calibrate the new module. Good luck with the repair!

Thanks for sharing your experience! That's really helpful since it sounds exactly like what I'm dealing with. Did you remember roughly how much you ended up paying for the pedal module replacement and calibration? Also, has everything stayed running smoothly since the fix, or have you noticed any other related issues popping up? Just want to make sure I'm prepared for what might come next with my M3.

Hey again! Glad to give you an update! So yeah, after getting my M5 checked out, it turned out I had both issues, the throttle valve and the accelerator pedal module were acting up. Got them both sorted and I can tell you the exact cost: paid 265€ for fixing the accelerator pedal module. Honestly, it was worth every penny because the car's been running like a dream since then. Been about a year now and absolutely zero issues, no more limp mode, no jumpy idle, throttle response is crisp and clean. The mechanic did a proper job on both the throttle valve and pedal module, and the calibration was spot on. It's like having a completely different car now! Trust me, once you get this fixed, you'll feel the difference right away. My M5 feels as responsive as it did when I first got it. Just make sure whoever does the work knows their way around BMW electronics, that's really crucial for getting everything calibrated correctly. Let me know how it goes with your M3!

Thanks so much for all the details! Just got back from the mechanic and you were spot on. Took my M3 to a BMW specialist and they found both issues, exactly like your case. Paid slightly more, around 300 for the full fix, but worth every penny. The whole experience was way better than my last mechanic. The fun part was testing it afterward, what a difference! No more limp mode, and the throttle response is amazing now. The idle's smooth as silk too. The mechanic explained everything clearly and even showed me the old parts. Really glad I asked here first, saved me from going down the wrong path with guesswork. Funny thing is, the mechanic mentioned these issues are pretty common in our generation of BMWs. Guess we both got lucky finding the right fix! Thanks again for helping me avoid another bad repair experience.