Ford PATS, the short version
- ✓PATS stands for Passive Anti-Theft System, fitted to every UK Ford since 1998
- ✓Four generations exist, each with a different transponder chip
- ✓Ford after 2004 uses the HU101 blade. Before that, FO21 Tibbe
- ✓Gen 3 enforces a 10-minute security delay. Gen 4 enforces up to 20
- ✓UK Ford remotes transmit at 433 MHz
What is the Ford PATS system?
Ford PATS is the Passive Anti-Theft System, the immobiliser fitted to every UK Ford since 1998. PATS reads a transponder chip in the key and releases the engine only when the chip identity matches a stored record.
The system runs independently of the remote buttons. A Ford key carries two circuits, a transponder that answers PATS, and a radio transmitter that operates the locks. Either one fails without affecting the other.
PATS explains the most common Ford key complaint. A blade cut at a counter turns the ignition barrel and leaves the engine dead, because the barrel is mechanical and PATS is not.
What are the 4 Ford PATS generations?
Ford fitted four PATS generations across UK vehicles between 1998 and the present. Each generation changed the transponder chip, and two of them added a timed security delay.
The table below sets each generation against its production years, chip, blade and programming route.
| PATS generation | Years | Transponder chip | Blade | Programming route |
|---|---|---|---|---|
| PATS Gen 1 | 1998 to 2007 | Texas Fixed 4C, ID4C | FO21 Tibbe, FO38 | OBD, 10-minute timed procedure |
| PATS Gen 2 | 2004 to 2011 | Texas Crypto 4D63 40-bit | HU101 | OBD with incode and outcode |
| PATS Gen 3 | 2011 to 2018 | Texas Crypto DST80 80-bit | HU101 | OBD, 10-minute security delay |
| PATS Gen 4 | 2017 onward | HiTag Pro ID47, ID49 128-bit | HU101, proximity | OBD plus RFA module access |
Model year decides the generation rather than model name. A 2014 Focus sits in Gen 3 and a 2018 Focus sits in Gen 4, which changes both the chip and the time the work takes.
What chip does a Ford key use?
A Ford key uses one of four transponder chips: Texas Fixed 4C on 1998 to 2007 vehicles, Texas Crypto 4D63 40-bit on 2004 to 2011, Texas Crypto DST80 80-bit on 2011 to 2018, and HiTag Pro ID47 or ID49 on 2017 onward.
Eight Ford lines cover the majority of UK vehicles. The table below lists the chip, blade and frequency for each.
| Ford model | Years | Chip | Blade | Frequency |
|---|---|---|---|---|
| Fiesta Mk6 | 2008 to 2017 | 4D63 40-bit, later DST80 | HU101 | 433 MHz |
| Fiesta Mk8 | 2017 to 2023 | HiTag Pro ID49 | HU101 | 433 MHz |
| Focus Mk2 and Mk3 | 2004 to 2018 | 4D63, later DST80 | HU101 | 433 MHz |
| Focus Mk4 | 2018 onward | HiTag Pro ID49 | HU101 | 433 MHz |
| Kuga | 2012 onward | DST80, later ID49 | HU101 | 433 MHz |
| Transit and Transit Custom | 2006 onward | 4D63, DST80, ID49 | HU101 | 433 MHz |
| Mondeo | 2007 to 2022 | 4D63, later DST80 | HU101 | 433 MHz |
| Ka and Fiesta Mk5 | 1998 to 2008 | Texas Fixed 4C | FO21 Tibbe | 433 MHz |
Encryption strength rose with each step. The 4C chip carries a fixed code, the 4D63 carries 40-bit crypto, the DST80 carries 80-bit, and HiTag Pro carries 128-bit, which is why the later generations resist cloning entirely.
Frequency mismatch on imported fobs
UK Ford vehicles transmit at 433 MHz. North American Ford fobs use 315 MHz. A 315 MHz fob pairs to PATS and starts the engine, and the remote buttons never operate the locks. The frequency prints on the FCC label inside the casing.
Which blade profile does a Ford key use?
Ford vehicles built after 2004 use the HU101 blade. Vehicles built between 1998 and 2007 use the FO21 Tibbe six-disc profile or the FO38 profile, each requiring dedicated cutting tooling.
The HU101 carries an eight-cut track on both faces, milled from a key code rather than traced from an existing blade. FO21 Tibbe carries a circular six-disc profile instead of a flat track, and Tibbe cutting uses a separate jig from HU101.
Ka, Fiesta Mk5, Transit Connect and Focus Mk1 carry the Tibbe profile. Every Ford line after them moved to HU101.
Why does Ford key programming take so long?
Ford key programming takes 25 to 90 minutes because PATS enforces a timed security delay on the later generations. Gen 3 enforces 10 minutes and Gen 4 enforces up to 20.
The delay is part of the security design rather than a tool limitation. No diagnostic platform shortens it, and the countdown runs before the module accepts a write.
| PATS generation | Security delay | Effect on the job |
|---|---|---|
| Gen 1 | None | 10-minute timed sequence completes the write |
| Gen 2 | None | Incode and outcode exchange runs immediately |
| Gen 3 | 10 minutes | Delay runs before the write is accepted |
| Gen 4 | Up to 20 minutes | RFA module access adds to the delay |
Gen 1 and Gen 2 vehicles complete in 25 to 40 minutes. A Gen 4 all-keys-lost job reaches 90 minutes once the RFA module access and the delay are both accounted for.
Does Ford MyKey affect a new key?
Ford MyKey requires reconfiguration after a new key is programmed on 2010-onward vehicles. MyKey stores speed limits, audio volume caps and seatbelt reminders against a specific key identity, and a fresh key defaults to administrator status.
Ford introduced MyKey to the UK range in 2010. The feature appears on the Fiesta, Focus, Kuga, Mondeo and Transit Custom. Reconfiguration runs through the same OBD session as the key programming.
Which costs, routes and scenarios follow from the generation?
Three practical questions follow once the generation is known, what a replacement costs, whether a dealer or an independent technician completes it, and what changes when no key survives at all.
What does car key replacement cost on a Ford?
Car key replacement cost on a Ford runs £80 to £300. A Fiesta Mk6 spare sits at £80 to £110. A Focus Mk4 with no surviving key reaches £220 to £300.
Generation drives the spread more than model. Gen 2 vehicles accept OBD programming directly, while Gen 4 vehicles add RFA module access and the longer security delay.
| Ford line | Spare key | No surviving key |
|---|---|---|
| Fiesta Mk6, Focus Mk2 and Mk3 | £80 to £120 | £150 to £220 |
| Mondeo, Transit | £90 to £170 | £160 to £270 |
| Fiesta Mk8, Focus Mk4, Kuga | £120 to £200 | £200 to £300 |
Is a Ford dealer or a Ford auto locksmith quicker?
A Ford auto locksmith completes the work the same day at the vehicle. A Ford dealer orders the key in, which places a working vehicle three to fourteen days away.
Recovery separates the two routes further. A Ford with no working key sits immobilised, so the dealer route adds £100 to £300 in recovery before the key charge applies.
How are lost car keys replaced on a Ford?
Lost car keys on a Ford are replaced through five operations at the vehicle, running 25 to 90 minutes depending on the PATS generation.
Read the PATS generation from the registration
The registration returns the model year, which places the vehicle in one of four PATS generations. Generation decides the chip, the blade and the programming route before anyone travels.
Decode the blade profile
Ford vehicles after 2004 use HU101. Vehicles between 1998 and 2007 use the FO21 Tibbe six-disc profile, which requires separate cutting tooling.
Read the PATS module over OBD
The diagnostic session reads the PATS module, the BCM, and on Gen 4 vehicles the RFA module that handles remote frequency.
Wait out the security delay
Gen 3 enforces 10 minutes. Gen 4 enforces up to 20. No diagnostic tool shortens either, and the countdown runs before the write is accepted.
Write the chip and erase missing keys
The new transponder identity writes into PATS memory, and the lost key identities are erased so an old key no longer starts the vehicle.
Step 5 closes the security gap. A Ford key stays valid in PATS memory until the identity is erased, which means a lost key continues to start the vehicle otherwise.
