Lear Smart Key Fob (FCC ID CWTWBU624) – ID46, 315 MHz Guide

Sourcing decisions for the Lear Smart Key Fob (FCC ID CWTWBU624) split between OEM and aftermarket paths, and each option carries distinct trade-offs in component quality and long-term reliability. An OEM unit from Lear Corporation uses factory-spec circuitry matched to the vehicle’s BCM, while aftermarket variants of this fob may differ in housing finish, button feel, or internal antenna characteristics. The Lear Smart Key Fob (FCC ID CWTWBU624) requires proper ID46 transponder registration and proximity pairing regardless of sourcing channel. For technicians evaluating the device before installation, verifying the FCC ID printed on the circuit board confirms authenticity. When replacing the Lear Smart Key Fob (FCC ID CWTWBU624), confirm that the operating frequency matches the 315 MHz specification expected by the target vehicle’s receiver module.

Technical Specifications of the Lear Smart Key Fob (FCC ID CWTWBU624)

This smart key operates at 315 MHz, which is the standard frequency allocation for keyless entry and push-to-start systems used in the North American market by Nissan and Infiniti during the model years this fob covers. The embedded transponder is an ID46 chip, a widely adopted crypto transponder that handles the immobilizer authentication handshake between the key and the vehicle’s engine control unit. Once the vehicle’s BCM recognizes the ID46 credential, the engine immobilizer releases, and ignition proceeds through the push-button start sequence.

The FCC ID CWTWBU624 is registered to Lear Corporation, a Tier 1 automotive supplier that has manufactured keyless entry and smart key hardware for several OEMs. This FCC registration confirms the device’s RF compliance at 315 MHz and verifies that it meets Part 15 emission limits for short-range communication devices.

Vehicle Fitment

Based on validated fitment data, this smart key is confirmed compatible with the following vehicles:

• Infiniti QX56/QX80 — 2008, 2009, and 2010 model years
• Nissan Armada — 2008 through 2015 model years

Both platforms share a common Nissan electrical architecture from this era, which explains the cross-compatibility of a single FCC-registered fob across two distinct nameplates. The QX56 (later rebadged QX80) and the Armada are built on closely related full-size SUV platforms, so the BCM hardware and immobilizer protocols are functionally identical for the purposes of smart key pairing.

Technicians should note that while the fob physically fits both vehicles, the programming procedure binds it to a specific VIN. A unit previously registered to an Armada cannot simply be moved to a QX56 without a full re-registration cycle through the vehicle’s diagnostic interface.

Programming and Registration Procedures

Registering the Lear Smart Key Fob (FCC ID CWTWBU624) to a vehicle requires a diagnostic scan tool capable of communicating with Nissan/Infiniti BCM modules. The standard workflow involves entering the BCM’s key registration mode, presenting each smart key to the start button antenna coil, and confirming successful ID46 transponder enrollment. Most professional-grade tools from major diagnostic platforms support this procedure under the Nissan immobilizer menu.

A critical step during programming is ensuring all existing keys are present and re-registered in the same session. The BCM typically overwrites its stored key list during each registration event, meaning any fob not presented during the procedure will be deactivated. For a vehicle owner who has lost one of their smart keys, this behavior actually serves as a security feature — the lost unit is effectively erased from the system once a new registration cycle completes with only the remaining valid fobs.

On-board programming (using an ignition-cycle sequence without a scan tool) is not supported for smart key systems on these platforms. The proximity-based start system requires scan-tool-level access to the BCM for any key addition or replacement. Automotive locksmiths servicing these vehicles should plan accordingly and confirm tool compatibility before arriving on-site.

OEM vs. Aftermarket Considerations

The OEM version of this fob, manufactured by Lear Corporation, is the benchmark for fit and function. Its internal antenna geometry is factory-calibrated for the specific proximity detection range expected by the Armada and QX56/QX80 platforms. Aftermarket alternatives exist and are commercially available, but they can vary in signal strength, which occasionally leads to reduced detection range — the vehicle may require the fob to be closer to the start button or door handle before responding.

From a transponder standpoint, the ID46 chip used in aftermarket units is generally sourced from the same silicon families as OEM, so immobilizer compatibility is rarely an issue. The more common failure point in lower-cost aftermarket fobs is the RF transmitter section, where component tolerances can drift enough to cause intermittent communication with the vehicle’s receiver. Locksmiths who stock aftermarket units should test range and response consistency before completing a customer handoff.

Regardless of sourcing, the physical emergency key blade — if one is integrated into the fob housing — should be tested in the driver’s door lock cylinder. This mechanical backup allows vehicle entry if the fob battery dies or the proximity system malfunctions.

Battery and Maintenance

Smart key fobs of this generation typically use a CR2025 or CR2032 coin cell battery, though the exact specification should be confirmed by opening the housing and checking the existing cell. Battery life under normal usage generally ranges from two to three years. When the battery weakens, the vehicle’s instrument cluster will display a key battery warning, and the effective proximity range will decrease noticeably before the fob stops functioning entirely.

Replacing the battery does not require re-programming. The ID46 transponder and RF pairing data are stored in non-volatile memory on the fob’s circuit board, so a simple battery swap restores full functionality immediately.

When to Contact a Locksmith

Vehicle owners needing a replacement for this smart key should contact an automotive locksmith experienced with Nissan and Infiniti push-to-start systems. Dealership programming is an option but typically costs significantly more than independent locksmith service. A qualified locksmith can source the correct fob, cut and verify any emergency blade, program the ID46 transponder to the vehicle’s immobilizer, and register the unit to the BCM — all in a single service visit.

For situations where all smart keys have been lost, the procedure becomes more involved and may require PIN extraction or seed-key security access through advanced diagnostic protocols. This scenario is best handled by a locksmith with dedicated Nissan/Infiniti tooling rather than a general-purpose code reader.