Chevy N300 Security Light Issue, Immobilizer Fault Fix?

Had the exact same immobilizer fault on my 2013 Chevy Spark last month. The security light kept flashing and the anti-theft system was going crazy. Turned out the key signal wasn't being properly recognized. Got it fixed at a workshop for around 45 Euro, the issue was incorrect key programming that needed to be reset. Pretty straightforward fix once they had the right diagnostic equipment. Key tip: Before taking it in, try this basic troubleshooting, leave your key in the ON position for about 10 minutes. Sometimes this resets the immobilizer. Didn't work for me, but worth a shot. What's the exact behavior of your security light? Does it flash constantly or only when trying to start? Also, have you had any recent battery issues? This could help narrow down if it's a similar problem to what I experienced. If you still have issues, definitely get those error codes read, they'll point to whether it's the immobilizer module or just a key programming problem.

Thanks for the detailed suggestions! Just had my 50,617 KM service done last month and everything was fine until now. The security light flashes constantly, even when the key is removed. Tried the 10-minute key trick but no luck. Haven't had any battery problems, it's actually pretty new, installed about 6 months ago. Will definitely get those codes pulled tomorrow. Good to hear it might just be a key programming issue rather than a full immobilizer replacement. Crossing fingers it's a quick fix like yours was.

Thanks for the extra info about your N300. Based on those symptoms, especially the security light flashing even with the key removed, it's definitely sounding like the same immobilizer issue I dealt with. The constant flashing typically points to a key signal problem rather than a full immobilizer failure. When I had this issue, my shop found that the transponder chip in the key wasn't communicating properly with the immobilizer module. The recent service might have somehow triggered this, sometimes disconnecting the battery during maintenance can mess with the key programming. For my Spark, they ended up having to resynchronize the key signal with the car's security system. The immobilizer bypass wasn't needed since the original system was fine, it just needed proper key programming to restore communication. Quick tip that worked temporarily for me before getting it fixed: Try using your spare key if you have one. Sometimes when the primary key's programming gets corrupted, the backup still works normally. Given the matching symptoms, I'd bet you're looking at a similar fix. Make sure the shop has experience with Chevy immobilizer systems specifically, some generic scan tools can't properly interface with the security modules. Keep us posted on what those error codes show!

Thanks everyone for the input. Just got back from the shop and wanted to update on my N300 situation. Turns out you were spot on, it was a key programming issue affecting the immobilizer system. The security light problem was fixed by reprogramming the transponder chip. Total cost was reasonable, definitely cheaper than replacing the whole immobilizer module. For anyone searching with similar issues: the remote start feature still works fine after the fix. They did mention I should consider getting a backup key programmed since I only have one working key now. The shop also cleared all the stored error codes and everything's running normally again. Really glad I checked here first, saved me from worrying it was something more serious with the car electronics. The constant flashing security light was definitely nerve-wracking, but it ended up being a pretty straightforward fix.