Ask a Car Question, Get an Answer ASAP!
Hello, I'm Jose Sebastian. Your mechanic automotive expert, it's a pleasure to me to attend your question. Thank you very much for trust in just answer.
Dear customer, would you tell me please if you have a light indicator on with the figure of a key? Do you have problems with your fob key battery? These is a very common problem in BMW with the immobilizer activate.
Dear customer, the first we have to dismiss is a problem with the immobilizer. Let me explain you a bit how it works.The electronic immobilizer protect your car through a chip programmed with a electronic code integrated to the key. It is compound of a unique code invariant and a second code that the immobilizer change each time the engine start on.When you start on the car, the immobilizer verify first the personal (unique) code and then the variant code. If both are correct, the immobilizer send an encrypted electronic signal to the DME ( Digital Motor Electronic) to unlock the engine. Without these signal, you cannot turn on the engine, even if you do a by-pass or short you cannot turn on the engine.As you can see, your problem is located in the immobilizer not in the key. The immobilizer is not changing the code at the moment you try to turn on the engine. These is a very common problem with BMW when the immobilizer present problems. This is the main cause of your starting on problem. The better way to dismiss these and other aspects that might be presenting as a problem in the fees of the starting system is with a BMW scanner tool. With the scanner you can reprogram the immobilizer or the starting system and check the error codes that your car could have at the moment.