Ford Smart Key Fob – ID49 Chip, 902 MHz | Key Details & Fitments

Used across a wide range of Ford auto locksmith and Lincoln vehicles from the mid-2010s era, the Ford Smart Key Fob serves as the primary keyless entry and push-to-start device for models including the Edge, Explorer, F-Series, Fusion, and Mustang. Each Ford Smart Key Fob integrates an NXP-manufactured ID49 transponder chip paired with 902 MHz RF communication, enabling both passive entry and engine immobilizer authentication. For automotive locksmiths, the fob demands precise programming procedures that synchronize the transponder with the vehicle’s body control module. Owners who need a replacement unit should be aware that dealer-level or advanced locksmith-grade diagnostic tools are required to register a new Ford Smart Key Fob to the vehicle.

Technical Specifications of the Ford Smart Key Fob

The transponder chip inside this remote is the ID49, produced by NXP Semiconductors. The ID49 platform uses AES-128 encryption for immobilizer handshake, which represents a significant step up from the older ID63 chips found in earlier Ford vehicles. This encryption standard makes the fob highly resistant to relay attacks and cloning attempts, which is a benefit for vehicle security but adds complexity to the programming workflow.

Radio frequency communication operates at 902 MHz, which is the North American band used by Ford for proximity-based passive entry. When the device is within range of the vehicle, the body control module sends an LF (low-frequency) wake-up signal. The fob responds on 902 MHz with an encrypted rolling code. This two-way exchange happens in milliseconds and allows the driver to unlock the doors by touching the handle and start the engine with the push-button ignition, all without removing the key from a pocket or bag.

Two FCC-registered transmitter IDs are associated with this product: M3N-A2C31243300 and M3N-A3C054339. These FCC IDs can be used to cross-reference replacement units and verify authenticity when sourcing parts. Locksmiths and parts specialists commonly reference these identifiers to confirm compatibility before beginning any programming procedure.

Vehicle Compatibility

The Ford Smart Key Fob covered here fits a specific set of validated Ford and Lincoln models. Below is the confirmed fitment list:

• Ford Edge — 2015 to 2017
• Ford Explorer — 2016 to 2019
• Ford F-Series — 2015 to 2017
• Ford Fusion — 2013 to 2016
• Ford Mustang — 2015 to 2017
• Lincoln MKC — 2015 to 2019
• Lincoln MKX / Nautilus — 2007 to 2015
• Lincoln MKZ — 2006 to 2012

It is worth noting that some of the Lincoln fitments — particularly the MKZ (2006–2012) and MKX (2007–2015) — predate the broader rollout of the ID49 chip across the Ford lineup. These earlier Lincoln applications may have transitioned to the ID49 platform during mid-cycle refreshes, so verifying the exact transponder type by VIN or physical inspection remains a best practice before ordering a replacement.

Programming Considerations for Locksmiths

Enrolling this fob to a vehicle requires access to a diagnostic tool capable of communicating with Ford’s PATS (Passive Anti-Theft System) module. Standard OBD-based key programmers that support Ford ID49 registration — such as the Autel IM608 Pro, Smart Pro, or equivalent platforms — are typically needed. The procedure involves placing the vehicle into a learning mode, presenting the new device, and allowing the PATS module to write the transponder’s unique cryptographic seed into its memory.

One detail that frequently trips up less experienced technicians is the distinction between adding a key to an existing set versus performing an all-keys-lost procedure. When at least one working fob is present, the enrollment process is comparatively straightforward: the existing key authenticates the session, and the new fob is registered alongside it. Without a working key, the diagnostic tool must bypass the authentication layer, which requires updated software tokens on many platforms and can extend the job time significantly.

Because the ID49 chip relies on AES-128 rather than the older DST-based encryption, cloning is not a viable method. Each fob must be individually registered to the vehicle’s immobilizer. Technicians accustomed to the clone-and-go workflow of older Ford transponders will need to adjust their process accordingly.

OEM vs. Aftermarket Considerations

Original equipment manufacturer versions of this remote carry the Ford or Lincoln branding on the casing and are typically sourced through dealership parts departments. Aftermarket alternatives exist and are often available at a lower price point. When evaluating aftermarket units, the critical factors are whether the internal transponder is a genuine NXP ID49 and whether the RF transmitter matches the 902 MHz frequency and one of the registered FCC IDs (M3N-A2C31243300 or M3N-A3C054339).

Aftermarket fobs that use compatible but non-identical chip architectures can sometimes register to the PATS module but may exhibit intermittent issues with passive entry range or engine start reliability. Locksmiths who regularly service Ford vehicles generally recommend confirming the chip specification before committing to a programming session, as a mismatched transponder will waste time and erode customer confidence.

When to Contact a Locksmith

Vehicle owners who have lost all copies of the fob, need a spare programmed, or are experiencing intermittent communication failures between the key and the vehicle should contact a qualified automotive locksmith. Dealerships can also perform programming, but independent locksmiths with the right tooling often provide faster turnaround and more competitive pricing, especially for on-site service.

Before scheduling service, owners should have the vehicle identification number (VIN) ready. The VIN allows the locksmith to confirm exact compatibility, verify the correct FCC ID variant, and prepare the appropriate programming tokens in advance. This step reduces on-site time and helps avoid compatibility surprises.