Lear 4-Button Remote Head Key (FCC ID CWTWB1U322) – FO21 Blade

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

Fitments for the Lear 4-Button Remote Head Key (FCC ID CWTWB1U322) include the Jaguar XK (1996–2006) and the Jaguar S-Type (1999–2007). Across both of these British luxury platforms, the unit handles keyless entry and engine-start authorization through a 315 MHz RF link paired with a physical FO21-profile blade. Each Lear 4-Button Remote Head Key (FCC ID CWTWB1U322) communicates with the vehicle’s body control module during a coded handshake, triggering door lock, unlock, trunk release, and panic functions across its four buttons. Owners replacing the fob should expect a professional programming session that registers the remote’s rolling code with the vehicle’s receiver. When ordering a Lear 4-Button Remote Head Key (FCC ID CWTWB1U322), confirm the FCC ID stamped on the back of the housing matches CWTWB1U322 to avoid cross-compatibility issues with visually similar Lear remotes.

Lear 4-Button Remote Head Key (FCC ID CWTWB1U322) — Technical Overview

Manufactured by Lear Corporation, this remote head key integrates a traditional cut-metal blade with an electronic remote module in a single housing. The FO21 keyway — a tibbe-style profile featuring six cylindrical positions — is the mechanical side of the equation. Because tibbe keys require a specialized cutter capable of indexing each position at the correct depth, most standard key machines cannot duplicate the blade. Automotive locksmiths equipped with a tibbe code cutter or a Lishi FO21 decoder/pick tool are the typical professionals who handle blade origination and duplication for this product.

On the electronic side, the remote operates at 315 MHz, which is the standard North American frequency band for vehicle keyless-entry systems of this era. The four-button layout maps to lock, unlock, trunk release, and panic — a configuration shared across many late-1990s and early-2000s luxury vehicles. The device transmits a rolling code that the vehicle’s receiver validates before executing the requested function, preventing simple replay attacks.

Vehicle Compatibility: Jaguar XK and S-Type

The Jaguar XK produced between 1996 and 2006 and the Jaguar S-Type produced between 1999 and 2007 are the validated fitments for this key. Both models were part of Jaguar’s lineup during a period when Lear Corporation supplied electronic key modules to multiple OEMs, and the CWTWB1U322 FCC registration covers remote assemblies delivered specifically for these Jaguar platforms.

On the XK, the remote head key serves as the primary entry and ignition device. The XK’s coupe and convertible body styles share the same immobilizer architecture for a given model year, so the same key part number applies regardless of body variant. The S-Type, Jaguar’s mid-size sport sedan, uses a comparable body control module setup. Locksmiths working on either vehicle should verify the existing key’s FCC ID before ordering a replacement, since Jaguar used several visually similar remotes across overlapping production years.

FO21 Keyway and Blade Cutting

The FO21 keyway is a tibbe-style key profile originally developed for Ford Motor Company platforms. Jaguar’s use of this keyway reflects the Ford-era ownership of the brand during the years these vehicles were manufactured. Unlike standard pin-tumbler automotive keys, tibbe keys feature a round shaft with six disc positions, each cut to one of several depth increments. The key rotates in the lock cylinder, and the discs must align at the correct depths for the sidebar to retract.

For locksmiths, cutting an FO21 blade requires either a dedicated tibbe key machine — such as an Ilco Orion or a Silca Triax — or a manual Lishi FO21 pick-and-decode tool that reads the existing lock wafer positions directly. Code cutting from the vehicle’s key code is also an option when the code is available from the VIN or a code retrieval service. The blade blank must match the FO21 profile exactly; using an incorrect blank will prevent mechanical operation even if the electronic pairing is successful.

Programming and Registration

Adding or replacing this remote head key on a Jaguar XK or S-Type typically requires a diagnostic tool capable of communicating with the vehicle’s security module. The remote’s rolling code must be registered so the body control module recognizes transmissions from the new device. Depending on the model year and the specific immobilizer generation, the procedure may involve on-board programming steps initiated through the ignition cycle or may require a scan tool session through the OBD-II port.

Because the mechanical blade and the remote module are integrated into a single housing, the key must be both cut and programmed before it is functional. A locksmith visit or dealership appointment addresses both steps in a single service call. Vehicle owners who purchase the key independently should be aware that the remote will not operate out of the box — professional programming is a required step, not an optional one.

Aftermarket vs. OEM Considerations

Aftermarket versions of this remote head key are available and typically cost substantially less than OEM-sourced units. Provided the replacement carries the correct FCC ID — CWTWB1U322 — and uses the proper FO21 blade blank, an aftermarket unit should program and function identically to the original. Quality variations between aftermarket suppliers do exist, particularly in button membrane durability and case fit. Locksmiths who stock this part regularly recommend inspecting the blade channel and battery compartment seal before committing to a specific supplier’s version.

OEM replacements sourced through Jaguar parts departments carry a higher price point but offer guaranteed housing tolerances and membrane quality. For vehicle owners who prioritize longevity and exact factory appearance, the OEM route may justify the premium. Either way, the programming procedure remains the same regardless of whether the key is OEM or aftermarket.

When to Contact a Locksmith

A professional automotive locksmith is the most practical resource for obtaining and programming a replacement for this Lear remote head key. Dealership service departments can also perform the work, though mobile locksmith services often provide faster turnaround and lower total cost. Key scenarios that require professional intervention include complete key loss, a key with a cracked or non-functional remote housing, and situations where the existing blade is worn beyond reliable mechanical operation. Because the FO21 tibbe blade demands specialized cutting equipment, this is not a do-it-yourself project for most vehicle owners.

Related help: car key replacement, car key programming.

Compatible and related keys: compatible Jaguar Remote Head Key.