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The Jaguar XJ in X350 and facelifted X358 form was on sale from 2003 right through to 2009 and was the first XJ built on a fully aluminium monocoque chassis. It sits in an interesting place from a key programming point of view because it pre dates the modern smart proximity era and runs an early generation transponder and remote system that most general locksmiths simply do not stock the correct virgin keys for. AJ Auto carries specialist software and the correct virgin keys for both the X350 and the X358, which makes us one of the very few options outside a main Jaguar dealer that can properly handle the platform. Our mobile technicians cover every model year from 2003 to 2009 across all engine variants including the supercharged XJR, attend anywhere in the UK and almost always finish the job the same day with no lock module replacement and no need to recover the vehicle.
For an X350 or X358 XJ spare key or a replacement for a lost or damaged remote, our mobile workshop attends your location with dealer-level JLR diagnostic software and the correct specification Jaguar key hardware for the platform. The X350 (2003–2007) and X358 facelift (2007–2009) use a 433 MHz transponder remote key system, and we carry compatible hardware for both build phases in the van. We programme the new remote on site, confirm central locking, engine start and the alarm all work correctly, and leave your existing keys fully active.
For all-keys-lost situations on the X350 or X358 we attend with full reset capability, clear the old key memory and programme fresh remotes in a single visit. No recovery truck or dealer booking is needed. Parts and programming carry a 12-month warranty and the price is fixed and agreed before we travel.
The X350 and X358 Jaguar XJ (2003–2009) use a Hitag2 transponder key system paired through the Body Control Module. The X358 facelift introduced a revised dashboard and updated infotainment but retained the same BCM-based key architecture as the X350. Both generations use a 433 MHz flip-style remote with a blade key, and programming requires manufacturer-level JLR diagnostic software — the BCM’s Hitag2 encryption cannot be accessed by standard automotive transponder programmers or non-JLR diagnostic tools.
Our technicians carry X350 and X358-compatible flip key remotes and connect a JLR SDD diagnostic interface to the OBD port. The programming sequence reads the current BCM security token, authenticates the new key and adds it to the approved list. For all-keys-lost situations we perform a complete immobiliser reset, generate new security seeds and programme fresh remotes from scratch. The X350 SuperV8 and XJR8 high-performance variants use the same BCM key system as standard models. X350/X358 key programming takes 15 to 30 minutes for a spare key and 30 to 45 minutes for all-keys-lost.
How does Jaguar XJ (X350/X358) key programming work and how long does it take?
Both the X350 and X358 use a Hitag2 transponder paired through the BCM. Our technician connects JLR diagnostic software to the OBD port, reads the existing security token and writes the new key into the approved list. A spare key takes 15 to 30 minutes; an all-keys-lost BCM reset and reprogram takes 30 to 45 minutes at your location.
What is the difference between the X350 and X358, and does it affect key programming?
The X358 is a facelift of the X350, introduced in 2007 with updated styling, revised infotainment and a restyled interior. The key security system — BCM, Hitag2 transponder and 433 MHz remote — is the same on both. Programming procedure and key hardware are identical, so whether your vehicle is a pre-facelift X350 or a post-2007 X358, the process and timescales are the same.
Can you programme a key for an X350 or X358 with the supercharged V8?
Yes. All X350 and X358 engine variants — including the 4.2 supercharged V8 in the XJR and SuperV8 — use the same BCM-based key system. Engine specification does not affect key programming. We carry compatible key hardware for all variants and the programming procedure is identical regardless of engine.
My X350/X358 blade key turns in the ignition but the engine won’t start — is this a transponder fault?
If the blade operates the ignition barrel but the engine will not crank or start, the most likely cause is a failed transponder chip or a BCM that no longer recognises the key token. We diagnose on site, test the transponder signal at the ignition coil, and either re-synchronise the existing key with the BCM or supply and programme a full replacement if the transponder has failed.
Will programming a spare key affect my existing X350/X358 remotes?
No. Adding a spare writes it into the BCM’s approved list without affecting your existing keys. All current remotes remain active. Only a full BCM reset in an all-keys-lost situation clears the list, and in that case all new remotes are programmed together in a single session.
Is there a warranty on X350/X358 key programming?
All parts and programming carry a 12-month warranty. If a programmed remote fails within the warranty period, we return to site at no charge. The fixed price quoted by phone covers all labour and hardware with no hidden fees.
We also cover other Jaguar XJ generations. If you need a key for the newer Jaguar XJ (X351), or for Jaguar sports and saloon models including the Jaguar XK/XKR (X150) and the Jaguar XF (X260), our mobile service covers all three alongside the X350/X358.
