Alfa Brera Diesel Won't Start: Immobilizer Issue Alert

I had the exact same symptoms with my 2013 Alfa 159 2.0 JTDm. The security light would flash when trying to start, engine would crank but not fire up properly. The immobilizer fault turned out to be causing the fuel cut-off, which is a common anti-theft system behavior when the key signal is not properly recognized. The issue was the transponder chip in the key not communicating correctly with the immobilizer control unit. A proper diagnostic revealed corrupted key data in the engine control module. This required complete reprogramming of both the key and the immobilizer system. This is definitely not a DIY job, it needs specialized diagnostic equipment and dealer-level programming capabilities. The remote start and central locking were also affected until the system was fully reset. What seemed like a simple key issue was actually quite serious since the immobilizer bypass procedure had to be done precisely to avoid damaging the security system further. The repair involved updating the engine control module firmware and reprogramming the transponder code sequence. My advice is to get it to a shop specializing in automotive security systems rather than a general mechanic, as improper programming attempts can make the situation worse.

Thanks for sharing your experience with the Alfa 159 immobilizer fault. That sounds exactly like what I am dealing with on my Brera. The security light behavior and starting issues match perfectly. Did you remember approximately how much the key programming and immobilizer bypass procedure cost? Also curious if you have had any related car electronics issues pop up since getting it fixed?

Had the repair done last week and very happy with the results. The immobilizer fault on my Alfa 159 was resolved completely for just 45 Euro, which covered the key programming correction. The security light no longer flashes and the car starts perfectly every time. The ignition control system is working flawlessly now, no more issues with the engine dying or failing to start. The anti-theft system communicates properly with the key, and I have not experienced any additional car electronics problems since the repair. The key programming service fixed the corrupted data that was causing the transponder chip to malfunction. Getting this done by a specialist who understands automotive security systems was definitely the right choice.

Thanks everyone for the helpful feedback. After reading about similar experiences, I took my Brera to a specialist who works specifically with car electronics and security systems. The diagnosis confirmed an immobilizer fault causing the starting issues. Total repair cost was 290 Euro, more than expected but worth it for a proper fix. The technician reprogrammed both keys and updated the ignition control module. Car starts perfectly now and the security light works normally. No more cranking issues or sudden stalling. The specialist also checked the entire anti-theft system to ensure everything was properly synchronized. Really glad I found a competent shop instead of risking further damage at a general mechanic. Will definitely use them again if I have any other electronic issues.