Audi RS3 Alarm Failure Linked to Battery System Issues

I experienced similar electrical issues with my 2017 Audi RS3. After the battery alarm system started acting up, the vehicle showed multiple warning lights including check engine. A diagnostic test revealed the original battery had deteriorated significantly, causing voltage fluctuations that affected the alarm system and engine management. The repair required: Full battery diagnostic test, Replacement of the original battery, Recalibration of the alarm system, Reset of the engine management system This is a relatively common battery problem in modern Audis as they have sophisticated electronics that are sensitive to voltage changes. While it was a serious issue that needed immediate attention to prevent potential electrical system damage, any qualified mechanic with proper diagnostic equipment can handle the repair. The job took about 2 hours to complete. The car battery needs to be coded to the vehicle after replacement, so the mechanic must have access to manufacturer-specific diagnostic tools. Regular mechanics can do this work if they have the right equipment, but dealerships are often better equipped for these electrical issues. Since fixing the battery problem, all systems including the alarm have functioned normally for the past 18 months.

Hey, that information is really helpful. I faced the exact same auxiliary battery issue with my RS3 a few months ago. The system diagnosis showed multiple electrical issues stemming from the failing battery. The technician mentioned this is quite common in newer Audis. Would you mind sharing how much the repair cost in your case? My car alarm problems got resolved, but Im curious if any other electrical issues popped up since your repair was done. Its been about 6 months since my fix and so far everything seems stable.

Happy to report that since having the work done, all electrical issues have completely cleared up. The auxiliary battery alarm system defective warning disappeared after the repair and hasnt returned in 18 months. The total repair came to 330 Euro, which covered replacing the aging car battery and recoding the system. No additional electrical issues have surfaced since the fix. The car battery check performed during my last service showed normal voltage levels, confirming the problem was fully resolved. The alarm system now works flawlessly, and all warning lights have stayed off. This type of electrical issue seems pretty standard with newer Audis. Getting it fixed properly the first time with a complete battery replacement and proper system coding appears to prevent any recurring problems.

Thanks for sharing the details. I finally took my RS3 to a certified Audi mechanic last week. The battery check confirmed what I suspected, a failing auxiliary battery causing the electrical issues. The total repair came to 380 Euro, slightly more than yours but included a full system diagnostic. The mechanic walked me through the entire process, showing how the failing battery was affecting multiple systems. They replaced the battery, recoded everything, and reset the car alarm system. The whole job took about 3 hours, but the results were worth it. All warning lights are now off, and the alarm system works perfectly again. From what the technician explained, this is indeed a common battery problem in newer models. They recommended getting regular battery checks during service to catch any voltage issues early. For anyone else facing similar issues, getting it fixed by a qualified mechanic who can properly code the new battery to the vehicle is crucial for a lasting solution.