Mercedes GLS Hybrid Immobilizer Problem

I had a similar issue with my older BMW 3 series. The symptoms were almost identical – engine refusing to stay running, error codes pointing to the immobilizer. Have you checked the battery voltage? A weak battery can sometimes cause spurious errors in the car electronics and trigger the immobilizer. Also, have you tried using your spare key to see if the issue persists? This could help isolate whether the problem is specific to the key itself or a more systemic issue.

Thanks for the quick reply. I'll check the battery voltage. I did try the spare key, but the problem is the same. Does that mean it's more than just a key programming issue? Did you have to do anything complex on your BMW, or was it simple?

Since the spare key didn't resolve the problem, it's likely not just a key issue. In my case, the BMW required a complete immobilizer system reset and re-programming at the workshop. Considering the potential complexity of modern car electronics and the potential for unintended consequences with DIY attempts, I would strongly advise against attempting an immobilizer bypass yourself. It's best to take your Mercedes to a qualified technician for proper diagnosis and key programming. They have the necessary tools and expertise to address the issue correctly.

I appreciate the advice that a workshop visit is best. I took it to a certified Mercedes technician. The key programming was corrupted and needed fixing. The reprogramming cost 45€. Thanks for sharing your experience; it helped me decide what to do.