Audi Q3 Alarm System Dead: Common Causes Revealed

Had a similar battery issue with my 2013 Audi Q5 last year. Have some experience working on basic car maintenance but needed professional help with the alarm system problems. The anti-theft system completely stopped responding, no lights, no confirmation beeps, nothing. After checking several components, the workshop found the alarm control module was incorrectly coded, specifically for the optical locking sequence. The indicators were not flashing when locking/unlocking the car, which was a clear sign something was wrong with the security alarm settings. The fix was relatively straightforward, they reprogrammed the alarm control module and recoded the optical locking function. Total cost was 45 Euro for the diagnostic and coding work. Since then, the system has worked flawlessly. Before suggesting more specific solutions, could you share: Have you noticed any other electrical issues recently? Does your key fob work normally for locking/unlocking? When did the problem first start, was it gradual or sudden? Are there any other warning lights on your dashboard? This information would help identify if your Q3 is experiencing the same coding issue or if there might be a different underlying problem with the alarm system components.

The service history shows the last maintenance was done at 72000km. I noticed this false alarm issue started occurring right after that. Initially thought it was just the immobilizer acting up, but the problem seems more complex. Interesting that you mention the optical locking sequence, as my indicators also stopped flashing completely when locking/unlocking. To answer your questions: No other electrical issues noticed, Key fob works fine for basic functions, Problem appeared suddenly, about 2 weeks ago, No warning lights on dashboard The security alarm situation is quite frustrating, especially since everything was working perfectly before the recent service. Thanks for sharing that repair cost reference, helps set expectations for the potential fix.

Thanks for those details. Based on your symptoms and timeline, this really sounds identical to my Q5 issue. The fact that it started right after maintenance is a telling sign, similar to what happened with my car, where the alarm sensor settings likely got disrupted during routine service work. The lack of indicator flashing despite the key fob working normally points strongly to an alarm control module coding issue. Since you have no other electrical problems or warning lights, we can probably rule out a more serious power failure or wiring problem. Quick tip from my experience: if the immobilizer is working correctly for starting the car, focus should be on the alarm control module rather than the entire anti-theft system. The module typically needs proper coding to sync with both the central locking and the optical feedback systems. The repair should be straightforward, mainly involving diagnostic work and recoding. Would expect costs to be similar to what I paid (around 45 Euro), assuming no physical components need replacement. While waiting for the repair, the car remains perfectly drivable since the basic security features are still functioning through the immobilizer. Recommend getting it checked soon though, as a non-functioning alarm system could affect insurance coverage in case of theft.

Thanks for the detailed response and sharing your Q5 experience. Your suggestion about the alarm control module coding makes a lot of sense, especially since my symptoms match yours so closely. The timing after maintenance and the specific issue with the indicators not flashing really does point to a coding problem rather than a hardware failure. Since the car is still under extended warranty, I will contact the workshop that did the recent maintenance. They should at least check if the alarm system programming was affected during their service work. The 45 Euro repair cost you mentioned seems reasonable if it falls outside warranty coverage. Will bring up the specific points about the alarm control module coding and optical locking sequence when I talk to them. Good to know the fix was straightforward in your case without needing replacement parts. Really relieved it is likely just a programming issue rather than a complete failure of the anti-theft system components. Thanks for helping narrow down the probable cause. Will update the thread once I get it sorted at the workshop.