The Mercedes-Benz blade key offers a straightforward solution for owners of 1997 C-Class, E-Class, S-Class, and SL models. While lacking remote unlocking features, this key allows manual door opening and engine starting without any programming requirements. This can be a significant advantage in situations where a remote key is lost or malfunctioning.
Understanding the 1997 Mercedes DAS System and Your Blade Key
The 1997 Mercedes models utilize the Drive Authorization System (DAS) for anti-theft protection. This system relies on an RFID chip embedded within the key fob or blade key. This chip, a PCF7935, communicates with the DAS control unit located behind the instrument cluster via an antenna around the ignition lock. Upon successful data exchange, the engine control unit (ECU) is authorized to start. The system also employs rolling code technology, updating the code with each use to enhance security.
A common issue arises when attempting to start the car with a weak or dying battery. The interrupted power supply can disrupt the code rewriting process within the RFID chip, potentially immobilizing the vehicle. Often mistakenly attributed to jump-starting, the root cause is the insufficient battery power affecting the sensitive RFID communication. Therefore, maintaining a healthy battery is crucial for preventing such scenarios.
The PCF7935 RFID chip is the essential component for key functionality. You can find its dimensions online. The circuit board within the key fob primarily handles remote locking features, which are absent in the blade key. If you have a functioning key fob, try holding it near the ignition lock while using the metal key – this might improve communication with the DAS system.
Programming and Reprogramming Options for Mercedes Blade Keys
For “all keys lost” situations, specialized devices, coupled with blank PCF7935 RFID chips, can program new keys to the DAS. However, reprogramming the DAS or ECU to accept units from different vehicles appears to involve more complex procedures, such as wiping or reprogramming the Vehicle Identification Number (VIN).
The 1997 diesel models often use a Bosch ECU, common in Volkswagen vehicles. Due to this wider application, reflashing the ECU to bypass the immobilizer system might be a viable option. Consult with a specialized Mercedes or Bosch technician for this procedure.
The blade key provides a basic, yet reliable method for accessing and starting your 1997 Mercedes. Understanding the underlying DAS system and the importance of the PCF7935 RFID chip is crucial for effective troubleshooting and key replacement. While the blade key lacks the convenience of remote functions, its simplicity and lack of programming requirements offer a dependable backup solution.
