VW Bora Immobilizer Starting Failure Fix Needed

Had a similar issue with my 2004 VW Golf, really frustrating when the car immobilizer acts up. As someone with basic car maintenance experience, I first tried the usual key signal reset procedure but that did not help. After some failed attempts, I took it to a workshop specializing in key programming and vehicle security systems. The diagnostic showed the key signal was not being properly recognized by the immobilizer system. They had to reprogram the key to sync correctly with the car immobilizer. Total repair cost was 45€ and fixed the starting issues completely. To help diagnose your case more precisely, could you share: Does the problem happen with all keys or just one? When did the issue first start? Have you had any recent work done on the electrical system? Does the security light stay on after starting attempts? The symptoms sound very similar, but proper diagnosis is important since immobilizer bypass issues can stem from different root causes. The key programming solution worked for my Golf, but your Bora might need a different approach depending on these details.

Last service was at 44000km and since then no major work done. The issue happens with both keys I have. The security light flashes rapidly during starting attempts and stays on after. Problem started about 2 weeks ago, gradually getting worse. No electrical work done recently. Really appreciate the feedback about key programming. Wonder if the immobilizer control module could be failing rather than just needing reprogramming. The car runs perfectly fine once it eventually starts, just getting it going is the challenge. Anyone know if these systems typically need full replacement or if programming alone usually resolves similar symptoms? The remote start function stopped working around the same time which seems related.

Thanks for those extra details about your Bora. My Golf actually showed those exact same symptoms, security light flashing rapidly and remote start failing before the main starting issues began. In my case, while key reprogramming helped temporarily, the problem eventually came back. It turned out the immobilizer fault was actually due to a failing control module, not just a programming issue. Had to replace the full immobilizer control unit which cost around 280€ plus programming. The fact that both your keys are affected and the remote start stopped working points strongly toward the control module rather than key issues. The immobilizer system on these VW models tends to show these classic signs when the module starts deteriorating, flashing security light, intermittent starting, and loss of remote functions. Before going for a full replacement though, worth having a specialist check if the anti-theft system connections are all secure. Sometimes corroded contacts in the module can cause similar symptoms and cleaning them can restore proper key signal reception. Going by my experience, I would recommend getting it checked soon as these problems tend to get worse until eventually the car might not start at all. The security light behavior you described is a typical warning sign of immobilizer control module failure in these models.

Thanks for sharing that detailed info about the Golf experience. Makes sense about the control module being the likely culprit rather than just key programming. The identical symptoms with flashing security light and remote start issues seem too similar to be coincidence. Think I will get it checked this week before it gets worse. The anti-theft system has been getting more temperamental and those corroded contacts you mentioned could definitely be the issue since the car lives outdoors. Really helpful to know the difference between just needing programming versus a full immobilizer fault repair. Will ask them to inspect the control module connections first before replacing anything. The 280€ cost for module replacement is not great but better than being stranded if the security light starts acting up even more. Hopefully just cleaning the contacts will resolve the key signal problems. If anyone else runs into similar starting problems with rapid security light flashing and failed remote start on these VW models, seems checking the immobilizer control module should be the first step. Will update once I get it sorted.