Honda OEM Transponder Key (chip ID46) – HON58R Blade Profile & Fitment

Used across select mid-2000s Acura platforms including the RL, TL, and TSX, the Honda OEM Transponder Key (chip ID46) serves as the factory immobilizer key for vehicles requiring HON58R blade-cut ignition access. Each Honda OEM Transponder Key (chip ID46) embeds a ceramic ID46 transponder chip inside the key head, which must handshake with the vehicle’s engine control module before the starter circuit will engage. For locksmiths and dealers, this key demands precise mechanical cutting and electronic registration to function correctly. A properly programmed Honda OEM Transponder Key (chip ID46) ensures seamless engine start authorization while maintaining the vehicle’s anti-theft integrity.

ID46 Transponder Technology in the Honda OEM Transponder Key (chip ID46)

The ID46 chip — sometimes referred to in the trade as a “Megamos Crypto” or “PCF7936” style transponder — is a fixed/crypto transponder widely deployed in OEM automotive security systems. In this key, the ID46 glass capsule sits encapsulated within the plastic bow of the key head, positioned so that the immobilizer ring antenna surrounding the ignition cylinder can interrogate it during key insertion and rotation. When the driver turns the key, the antenna energizes the passive chip, which responds with a rolling cryptographic exchange. If the engine control unit validates the response, fuel injection and ignition proceed normally. If the chip is absent, damaged, or unregistered, the vehicle’s immobilizer holds the engine in a no-start condition.

Because the ID46 is a transponder-only key — not a remote-head key or proximity fob — it carries no remote-lock buttons and requires no battery. The entire electronic function depends on passive inductive coupling at close range between the chip and the antenna coil. This simplicity makes the key mechanically robust, but it also means that a lost or damaged unit cannot be bypassed without professional equipment capable of reading the immobilizer system and writing a new transponder profile.

HON58R Keyway and Mechanical Cutting

The HON58R blade profile is a high-security sidebar keyway used on several Honda and Acura models from the mid-2000s era. Unlike older Honda key blanks such as HD106 or HD111, the HON58R features a narrower blade cross-section with tighter tolerances on the sidebar track. Cutting this key accurately requires either a code-cut machine with the correct Honda space-and-depth data or a precision duplicator with an original working key for reference.

Automotive locksmiths should note that HON58R differs from the visually similar HON66 blank. Mixing up these two profiles is a common shop-floor error — the blade may physically enter the cylinder but bind or fail to rotate if the wrong blank is used. Always verify the keyway before cutting to avoid wasted blanks and callbacks.

When cutting by code, the bitting information can typically be pulled from the vehicle’s door or trunk lock using an appropriate Honda decoder, or obtained via the VIN through authorized key-code databases. OEM-spec keys should match Honda’s published space and depth charts for the HON58R profile, with cuts falling within ±0.001″ of nominal to guarantee smooth cylinder operation over the life of the key.

Validated Vehicle Fitments

Based on confirmed fitment data, this key is compatible with the following Acura models:

• Acura RL — Model years 2005 through 2012
• Acura TL — Model years 2004 through 2008
• Acura TSX — Model years 2004 through 2008

All three of these vehicles share Honda’s mid-2000s immobilizer architecture, which relies on the ID46 transponder for engine start authorization. While the RL spans a broader production window (eight model years), the TL and TSX share a five-year range that corresponds to their respective generation cycles. Owners of these vehicles will find that the key’s mechanical and electronic specifications remain consistent across each model’s listed years, meaning a single SKU covers the entire span without variation.

Programming and Registration Procedures

Registering the transponder to the vehicle’s immobilizer system is a necessary step that cannot be skipped. Simply cutting the blade to the correct bitting will allow the key to mechanically turn the ignition cylinder, but the engine will not start until the ID46 chip has been enrolled in the ECU’s memory.

Professional locksmiths typically use a diagnostic tool or dedicated transponder programmer to perform this registration. The general workflow involves connecting the tool to the vehicle’s OBD-II port, reading the current immobilizer status, and then writing the new key’s transponder ID into an open slot in the ECU. Honda’s immobilizer system on these Acura models supports multiple key registrations, so adding a key does not necessarily erase existing keys — though procedures vary by tool manufacturer and software version.

Some technicians may also encounter scenarios where the vehicle has lost all registered keys. In an all-keys-lost situation for these Acura models, the process generally requires reading secured data from the immobilizer module (often via the ECU itself) and performing a full key rewrite. The specific steps and pin-code requirements depend on the diagnostic platform being used. Locksmiths unfamiliar with Honda’s immobilizer protocol for this generation should consult their tool’s procedure library before beginning work on-site.

OEM vs. Aftermarket Considerations

As an OEM-grade product, this key uses a factory-specification ID46 chip and HON58R blank. Aftermarket alternatives exist at lower price points, but quality can vary — particularly in the precision of the blade blank and the reliability of the embedded transponder. Cheaper clones sometimes use chips that present an initial handshake but degrade over time due to lower-quality encapsulation or inconsistent antenna coupling characteristics.

For vehicle owners, the practical implication is straightforward: an OEM-spec key is less likely to produce intermittent no-start conditions months after programming. For locksmiths, stocking genuine or high-quality OEM-equivalent blanks reduces warranty callbacks and protects professional reputation. The ID46 chip is mature technology at this point, so well-manufactured aftermarket chips can perform comparably — but sourcing from reputable transponder suppliers is essential.

When to Contact a Locksmith

Vehicle owners who need a replacement for their Acura RL, TL, or TSX ignition key should plan for both mechanical cutting and electronic programming. Dealerships can perform both services but typically at a higher cost and with longer turnaround times. A qualified automotive locksmith with Honda immobilizer experience and the appropriate diagnostic tools can usually complete the job on-site in under an hour, including blade cutting, transponder registration, and functional verification.

It is advisable to have a spare key made while the vehicle still has at least one working key. Adding a key to an existing registration is faster, less expensive, and avoids the complexity of an all-keys-lost recovery. The key should be tested not only for mechanical turn in the ignition but also for consistent engine start across multiple attempts before the technician leaves the job site.