The topic of BMW remote key programming is often surrounded by misinformation and misunderstandings. It’s crucial to clarify what’s possible and what’s not, especially when it comes to starting your BMW and utilizing remote functions. Many BMW owners wonder if they can simply program a used BMW remote key to work with their car. Let’s delve into the realities of BMW key programming and separate fact from fiction.
Understanding BMW Key Security Systems
BMW remote keys incorporate multiple systems, primarily the EWS (Elektronische Wegfahrsperre), which is the electronic immobilizing system, and the FZV (Zentralverriegelung), the central locking system, often linked with DWA (Diebstahlwarnanlage), the anti-theft alarm system. It’s vital to understand that these systems operate independently when considering key programming.
The EWS is designed as a robust anti-theft measure. Each BMW has a unique Vehicle Identification Number (VIN), and the EWS encryption is intrinsically linked to this VIN. This means that a BMW remote key is programmed at the factory with a unique, encrypted ISN (Individual Serial Number) that corresponds specifically to your car’s VIN. This encrypted information is stored within BMW’s secure database, accessible only to authorized BMW dealerships.
This VIN-specific encryption is the reason why you cannot program a “used” BMW remote fob to START another BMW. The EWS system will not recognize the key because the ISN encrypted within the used key does not match the VIN of your BMW. To obtain a new key capable of starting your BMW, you must go through an official BMW dealership’s parts department. They require proof of ownership and VIN information to order a new key, which is then programmed and shipped to the dealership for you to collect.
Reprogramming Remote Locking and Alarm Features
While starting the engine with a used key is impossible due to the EWS, the FZV and DWA systems for central locking and alarm are different. In some older BMW models, particularly those in the E series, it was possible to program a used remote, or a remote from another BMW, to operate the lock/unlock and arm/disarm functions of your car.
This reprogramming for locking/unlocking is contingent on the keys transmitting on the same radio frequency as your BMW’s receiver. In North America, the frequency is typically 315 MHz, while in Europe, it’s often 433 MHz. Even if you successfully reprogram a used key to lock and unlock your doors, it’s crucial to reiterate that the key will still not start the car because of the EWS immobilizer system.
The Write-Once EWS Transponder Chip
The limitation in reprogramming the starting function lies within the EWS transponder chip inside the BMW remote key. This chip is designed as a write-once chip. Even with aftermarket software and hardware capable of retrieving the ISN from your car’s DME (Digital Motor Electronics) and EWS control modules, you would still face the challenge of writing this ISN data to a new EWS transponder.
Examining older E-series “diamond shaped” remotes reveals that the EWS transponder is often soldered directly to the IC board within the key. While the internal structure of newer F and G series keys might differ, the fundamental principle of a write-once, VIN-specific transponder likely remains. This physical and technological security measure effectively prevents the reuse of BMW keys for starting different vehicles.
Conclusion: Secure Key Programming for BMW
In summary, programming a BMW car remote for starting purposes requires a new key ordered and programmed through an authorized BMW dealership due to the VIN-specific EWS immobilizer system. While older models might allow reprogramming of used keys for remote locking/unlocking functions if the radio frequencies are compatible, the engine starting function remains strictly controlled by the EWS and the write-once transponder chip. For key replacements or any starting-related key issues, consulting your BMW dealership is the necessary and secure route.
