Honda OEM 4-Button Remote Head Key (FCC ID MLBHLIK1T) – Key Guide

By Mohammad H. Abdelhadi, ALOA-Certified Master Locksmith, mobile automotive locksmith. Reviewed by Ray Obar, Master Locksmith. Updated June 1, 2026.

Sourcing decisions for the Honda OEM 4-Button Remote Head Key (FCC ID MLBHLIK1T) split between OEM and aftermarket paths, each with distinct trade-offs in durability, electronics quality, and long-term reliability. An OEM unit carries Honda’s factory-spec PCF7936 transponder and precisely cut HON66 blade profile, ensuring seamless communication with the vehicle immobilizer on first programming. Aftermarket variants of this remote head key may replicate the external shell and button layout but can differ in circuit board build quality and transponder consistency. The Honda OEM 4-Button Remote Head Key (FCC ID MLBHLIK1T) requires proper transponder registration and remote pairing regardless of sourcing origin. For technicians, every variant—whether genuine or third-party—must be validated against the target vehicle’s immobilizer before delivery to the customer. When replacing the device, confirm that the FCC ID MLBHLIK1T designation matches the vehicle’s expected remote protocol and that the 315 MHz operating frequency aligns with the receiver module installed in the dash.

Honda OEM 4-Button Remote Head Key (FCC ID MLBHLIK1T): Technical Specifications

This key operates on a 315 MHz radio frequency for its remote functions, which include lock, unlock, trunk release, and panic—the standard four-button configuration found on its validated fitments. The integrated transponder is a PCF7936 chip, a well-established passive transponder that communicates with the vehicle’s immobilizer antenna ring surrounding the ignition cylinder. Without successful transponder registration, the engine will crank but will not start, regardless of whether the mechanical blade turns the ignition.

The blade profile is HON66, a high-security sidewinder cut used across several Honda and Acura platforms from this era. Unlike traditional edge-cut keys, the HON66 features a serpentine milling pattern on the blade’s flat surface, requiring specialized cutting equipment such as a Lishi-style cutter or a code machine capable of internal-cut profiles. Locksmiths should verify bitting data from the vehicle’s door lock or ignition before cutting, as aftermarket blanks can vary slightly in tip-stop dimensions.

Validated Vehicle Fitments

The FCC ID MLBHLIK1T remote head key is confirmed to fit the following vehicles:

• Acura TL — model years 2009 through 2014
• Acura TSX — model years 2009 through 2014

Both the Acura TL and TSX from this generation share the same immobilizer architecture and remote receiver module, which is why a single FCC ID covers both platforms. Technicians working on either model will find that the programming procedure and transponder registration steps are functionally identical. It is worth noting that while these are Acura-branded vehicles, the key carries Honda OEM designation because Acura is Honda’s luxury division and sources its key components from the same Honda parts pipeline.

Programming and Transponder Registration

Registering the PCF7936 transponder in this remote head key requires a diagnostic tool capable of communicating with the Acura immobilizer ECU. On 2009-2014 TL and TSX models, the immobilizer system does not support on-board (customer-initiated) key learning. A professional-grade tool—such as those from Autel, Smart Pro, or the Honda HDS dealer system—is needed to write the transponder ID into the vehicle’s immobilizer memory.

The remote portion of the key—responsible for lock, unlock, trunk, and panic functions—is paired separately from the transponder. On these Acura models, remote pairing can sometimes be accomplished through an on-board procedure involving a specific ignition-cycle and button-press sequence within a timed window. However, if the vehicle has lost all previously programmed remotes, the on-board method will not work, and a diagnostic tool becomes mandatory for both transponder and remote registration.

Locksmiths should also be aware that the PCF7936 transponder in this key must be in a virgin (unprogrammed) state before registration to a new vehicle. If the chip has been previously written to another vehicle’s immobilizer, it will need to be erased or replaced before it can be enrolled in a different car. Some diagnostic platforms offer a chip-reset function; others require a fresh transponder entirely.

OEM vs. Aftermarket: Practical Considerations

The genuine Honda OEM version of this key provides the highest assurance of first-attempt programming success. OEM transponder chips are factory-calibrated and tested against Honda’s own immobilizer specifications, which reduces the risk of intermittent communication failures that can plague lower-quality aftermarket clones. The OEM shell also tends to have tighter tolerances on the battery compartment and button membrane, resulting in longer service life and more consistent button feel.

Aftermarket alternatives are widely available and significantly less expensive. Quality varies considerably across manufacturers. Higher-tier aftermarket remote head keys designed around the MLBHLIK1T specification use genuine PCF7936 transponder chips and replicate the 315 MHz remote circuit with reasonable fidelity. Budget options may substitute a compatible-but-not-identical transponder variant, which can introduce subtle programming difficulties. Automotive locksmiths who regularly service Acura TL and TSX vehicles often keep both OEM and trusted aftermarket units in stock to offer customers a choice based on budget and preference.

Blade Cutting Notes for the HON66 Profile

The HON66 keyway is an internal-cut (laser-cut or sidewinder) profile. Cutting requires either a dedicated code machine with HON66 jaws or a Lishi HON66 pick-and-decode tool for impressioning from the lock. When using code-cut methods, locksmiths should reference the key code stamped on the ignition lock or retrieve it from Honda’s key code database using the VIN. The code typically yields a series of depth values corresponding to the serpentine track on each side of the blade.

One common pitfall with aftermarket HON66 blanks is inconsistent tip-stop length. If the blank’s tip stop is even a fraction of a millimeter off from the OEM specification, the resulting cut will be shifted along the entire blade, causing binding in the ignition cylinder. Testing the mechanical blade in the ignition before beginning transponder programming saves time and avoids unnecessary diagnostic sessions for what is ultimately a cutting issue.

When to Contact a Professional Locksmith

Vehicle owners driving a 2009-2014 Acura TL or TSX who need a replacement remote head key should contact a qualified automotive locksmith rather than attempting to source and program the key independently. The transponder registration step cannot be completed without professional diagnostic equipment, and improper attempts can occasionally lock out the immobilizer ECU, requiring a more involved recovery procedure. A mobile automotive locksmith can typically cut the HON66 blade on-site, program the PCF7936 transponder, and pair the remote—all in a single service call at the vehicle’s location.

Related help: Acura auto locksmith, car key replacement, car key programming.

Compatible and related keys: Honda OEM Remote Key Fob (compatible fob), compatible Honda OEM Transponder Key (chip ID46), Honda OEM 4-Button Remote Key Fob (compatible fob), Honda OEM 4-Button Smart Key Fob (FCC ID M3N5WY8145), compatible Honda OEM Remote Head Key (FCC ID OUCG8D439HA), Honda OEM Transponder Key (chip ID13) (compatible fob), related key: Honda OEM 4-Button Smart Key Fob (FCC ID KR580399900), related key: Honda OEM Transponder Key (chip ID46), Honda OEM Remote Key Fob, Honda OEM 4-Button Smart Key Fob (FCC ID KR5T21).