The **MH64TAG-R** is a specific RFID (Radio Frequency Identification) transponder tag, commonly used in automotive security systems, specifically as part of an **immobilizer system**. These tags are used by manufacturers like **Suzuki, Mitsubishi, and Honda** for key-fob identification. --- ## 1. Technical Specifications The MH64TAG-R belongs to the **Hitag 3 (HT3)** family of chips developed by NXP Semiconductors. | Feature | Specification | | :--- | :--- | | **Technology** | RFID / Transponder | | **Operating Frequency** | 125 kHz (Low Frequency) | | **Chip Model** | PCF7961M / Hitag 3 (AES Encryption) | | **Data Transmission** | Bi-directional (Read/Write) | | **Modulation** | ASK (Amplitude Shift Keying) | | **Security Standard** | 128-bit AES Encryption | --- ## 2. Key Electronic Components Inside the plastic casing of an MH64TAG-R, you will find the following core electronic elements: ### A. The Integrated Circuit (IC) The "brain" of the tag is typically an NXP PCF series chip. * **EEPROM:** Stores the unique ID (UID) of the vehicle and the secret cryptographic keys. * **Logic Controller:** Handles the authentication handshake between the key and the car's ECU (Engine Control Unit). * **Voltage Regulator:** Converts the induced magnetic field into a stable DC voltage to power the internal logic. ### B. The Antenna Coil Since this is a **passive** RFID tag, it does not have a battery for the transponder function. * **Copper Micro-coil:** A fine wire wound around a ferrite core. * **Inductive Coupling:** It picks up energy from the electromagnetic field generated by the ignition lock cylinder (the "exciter" or "reader"). ### C. Resonance Capacitor * Connected in parallel with the coil to create an **LC Resonant Circuit** tuned exactly to **125 kHz**. This ensures maximum energy transfer and signal clarity. --- ## 3. Functionality & Security The MH64TAG-R is highly regarded for its security features compared to older 4D or 46-chip transponders. 1. **Passive Power:** The tag remains dormant until it enters the magnetic field of the car’s ignition coil. 2. **Challenge-Response:** The car sends a random "challenge" number. The MH64TAG-R processes this using its **128-bit AES key** and sends a "response" back. 3. **Immobilizer Bypass:** If the response matches the ECU's calculation, the fuel pump and ignition are enabled. --- ## 4. Common Applications * **Suzuki:** Swift, Vitara, S-Cross, Ignis (Post-2015/2016 models). * **Mitsubishi:** Various modern models using the "Smart Key" or "Flip Key" systems. * **Replacement:** Often sold as a "blank" chip that must be programmed using specialized locksmith tools (like Autel IM608 or VVDI Key Tool).