Jaguar Remote Head Key – 433 MHz FO21 Blade for S-Type, X-Type & XJ

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 Jaguar Remote Head Key split between OEM and aftermarket paths, each with trade-offs in cost, durability, and shell quality. An OEM unit from Jaguar Cars carries the factory blade profile and electronics housing, while aftermarket variants of this key typically replicate the same FO21 keyway and 433 MHz remote frequency at a lower price point. The Jaguar Remote Head Key requires professional programming to sync the integrated remote module with the vehicle’s receiver, regardless of whether the unit is OEM or aftermarket. For technicians evaluating either sourcing path, blade cut precision and remote signal reliability remain the two benchmarks that matter most. When replacing the Jaguar Remote Head Key, confirm that the FO21 blade blank matches the original and that the 433 MHz frequency aligns with the target vehicle’s specifications before beginning any programming procedure.

Vehicle Fitments for the Jaguar Remote Head Key

This key covers three core Jaguar platforms from the late 1990s through the late 2000s. Each of these vehicles used a remote-integrated key design that combined mechanical ignition access with wireless lock and unlock functions in a single housing.

• Jaguar S-Type (1999–2007) — The S-Type was Jaguar’s mid-size executive sedan, and throughout its production run it relied on FO21-profile keys with 433 MHz remote operation. This fob is a direct replacement for the factory unit on all model years within this range.
• Jaguar X-Type (2001–2009) — Jaguar’s compact entry sedan, the X-Type, shares the same remote head key platform. The device slots into the same ignition barrel and communicates on the same 433 MHz band used across the lineup.
• Jaguar XJ (2003–2009) — The XJ flagship sedan from this era also utilizes this key style. Despite the XJ’s premium positioning, the remote head key hardware is functionally interchangeable with the S-Type and X-Type units in terms of blade profile and radio frequency.

Across all three platforms, the mechanical side of this key uses the FO21 keyway — a Ford-family blade profile that Jaguar adopted during its period under Ford Motor Company ownership. Locksmiths familiar with FO21 cutting will find the blade dimensions and depth specifications consistent with other Ford-group vehicles of the same era.

FO21 Blade Profile and Mechanical Details

The FO21 keyway is a tibbe-style sidebar blade commonly associated with Ford and its subsidiaries during the late 1990s and 2000s. On these Jaguar models, the blade engages a sidebar ignition lock cylinder rather than a traditional pin tumbler. Cutting an FO21 blade requires a tibbe key machine or a code cutter calibrated for the FO21 depth and spacing specifications. Most automotive locksmith shops that service Ford-era vehicles will have the necessary tooling on hand.

When cutting a replacement blade, it is critical to use the original key or an accurate key code as the reference. Worn blades on high-mileage Jaguars from this era can produce inaccurate impressions if used as a direct copy template. Where possible, pulling the code from the lock cylinder or using a factory key code lookup yields more reliable results.

433 MHz Remote Functionality

The integrated remote module in this key operates at 433 MHz, which is the standard frequency for European-market and many global-market Jaguar vehicles from this period. The remote head design means the transmitter board, battery, and antenna are all housed within the key shell itself — there is no separate fob to carry.

Battery replacement is straightforward on most versions of this unit. The shell typically splits along a seam, revealing a coin-cell battery (commonly CR2032 or similar, depending on the specific shell variant). After battery replacement, the remote should not require reprogramming — only the transponder and remote pairing require professional equipment.

If the remote portion stops functioning but the mechanical blade still starts the vehicle, the issue is usually a dead battery or a damaged transmitter board. In cases where the board has failed, a replacement remote head key shell with a new board is the standard repair path.

Programming Considerations

Programming this key to the vehicle involves two separate procedures: syncing the remote (lock/unlock) functions and, if the unit contains a transponder, registering the immobilizer component. The remote pairing procedure on S-Type, X-Type, and XJ models from this era typically requires a diagnostic tool capable of communicating with the vehicle’s body control module. Some year ranges support on-board programming sequences initiated through the ignition switch, but this varies by model and production year.

Automotive locksmiths should consult model-specific programming guides before beginning work, as the S-Type, X-Type, and XJ each have slightly different module architectures despite sharing the same physical key platform. A diagnostic tool with Jaguar software coverage — such as those offered by major aftermarket scan tool manufacturers — is the most reliable approach.

For vehicle owners, the key takeaway is that this is not a DIY-programmable key in most cases. Professional locksmith or dealer programming is recommended to avoid incomplete pairing, which can leave the remote non-functional or, worse, lock out existing working keys from the system.

OEM vs. Aftermarket: What to Expect

OEM replacements sourced through Jaguar dealerships come pre-cut or ready to cut, with a factory-spec transmitter board and shell. The premium cost reflects guaranteed compatibility and material quality. Aftermarket options for this key are widely available and generally replicate the FO21 blade blank and 433 MHz remote board accurately, though shell fit and button feel can vary between manufacturers.

When selecting an aftermarket unit, confirm that the remote board is rated for 433 MHz — some generic remote head key shells are sold with 315 MHz boards intended for North American Ford applications and will not function on these Jaguar models. This is the single most common sourcing error locksmiths encounter with this product category.

Regardless of origin, all replacement units require the same programming steps. There is no shortcut for OEM keys versus aftermarket keys in this regard — the vehicle’s electronics do not distinguish between the two once the key is properly paired.

When to Call a Locksmith

Vehicle owners dealing with a lost, damaged, or non-functional key for an S-Type, X-Type, or XJ from the covered model years should contact an automotive locksmith with Jaguar experience. Mobile locksmith services can typically cut the FO21 blade and program the remote on-site, eliminating the need for a dealership visit and often at a significantly lower cost.

Before scheduling service, owners should note their exact model year, as this determines the specific programming protocol required. Having the VIN available speeds up the process and helps the locksmith verify key code information before arriving on-site.

Related help: car key replacement, car key programming.

Compatible and related keys: Lear 4-Button Remote Head Key (FCC ID CWTWB1U322).