Ducati ST2, ST3, ST4 and ST4S Key Replacement

Quick answerThe Ducati sport-tourers straddle two key eras. Ducati's owner's manual covering the ST2 and ST4 describes two plain universal keys, while the ST4S and ST3 manuals describe an immobilizer with chipped keys and a Code Card. So the year and model decide whether a lost key is a simple cut or a cut plus programming. A quick look at the dash and your key set usually settles it.

Ducati ST2, ST3, ST4 and ST4S key quick facts

The owner's manual covering the ST2 and ST4 says the bike was delivered with two universal keys for the ignition, steering lock, tank filler plug and seat catch, plus a key identification plate.
The ST4S owner's manual has an immobilizer chapter: a CODE light on the dash flashes briefly when the key is recognized and stays on when it is not.
On the ST4S the Code Card carries two things: the electronic code for an emergency start and the mechanical code for the keys.
The ST3 manual describes the same idea with an IMMO light, a Code Card and a duplicate-key procedure at Ducati Service covering up to 8 keys.
Ducati's dealer bulletin lists the ST3 and ST3 S under the three-key IRC system.

Ducati ST2, ST3, ST4 and ST4S key types by year

Years	Models	Key type	Chip	Notes
1997-2001	ST2, ST4	mechanical cut key	no	Two universal keys and an identification plate in the owner's manual that covers both the ST2 and ST4.
2002-2003	ST2, ST4	plain or transponder, by bike	varies	Ducati phased the immobilizer in around these years. Look for a red key or a Code Card, tell us the year, and we confirm.
2001-2005	ST4S, ST4S ABS	master key plus black transponder keys	yes	Immobilizer, CODE light and Code Card in the ST4S owner's manuals, including the 2001 edition. The manual's key A is the master key that reprograms the black keys.
2004-2007	ST3, ST3 S	red master key plus two black transponder keys	yes	IRC with Code Card.

Which ST do you have?

Three checks sort an ST into the right group without tools. First, the keys: a red key, or a Code Card in the paperwork, means the bike has the immobilizer. Second, the dash: the ST4S manual describes a CODE light and the ST3 manual an IMMO light that flashes briefly at key-on. Third, the manual itself: the early books open the controls chapter with plain universal keys and never mention a code.

If the bike has passed through several owners and the paperwork is gone, give us the year and VIN and describe what happens on the dash when you turn the key.

Need a key for your ST2?

Call or text with the year and where the bike is parked.

Call (805) 429-8452 Text your year, make and model

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Locks on the sport-tourers

The ST4S manual places the ignition switch in front of the fuel tank and gives it four positions, the last being P for the parking light with the steering locked.

Ignition switch and steering lock
Tank filler plug: the key turns a quarter turn clockwise to unlock
Seat catch: a quarter turn clockwise until the rear of the seat lifts
Helmet hooks under the seat, used with the helmet fastening cable from the tool bag
Side panniers, where fitted, came as a kit with their own instructions; tell us whether yours are Ducati cases and whether they still match the ignition key

Panniers and mismatched keys

Luggage is another place where keys get mismatched. Cases get added years after the bike was sold, bought used from another ST, or replaced after a tip-over, and each set can bring its own key. If you are carrying one key for the bike and another for the bags, the case locks can usually be rekeyed to the bike's key. If the case key is the one you lost, the bike's ignition key may or may not help, so mention the luggage when you call.

Lost keys: plain-key bikes and immobilizer bikes

On an early ST2 or ST4 with universal keys, we cut a key to the locks on the bike and you are riding again. Nothing needs programming.

On an ST4S or ST3 the cut key also needs a chip the bike accepts. The ST manuals say to contact Ducati Service with all remaining keys and the Code Card, and that keys not presented have their codes erased. Adding keys the factory way depends on the red key, so tell us whether you have it. Either way we need photo ID and the registration or title, and a charged battery on the bike.

Where to find the key code

Early bikes came with a key identification plate. Immobilizer bikes came with a Code Card, and the ST4S manual says the card shows both the electronic code and the mechanical code for the keys, to be reported to the Ducati Service network when ordering.

What to have ready

Have this ready when you call or text

Year, make and model of the bike
Where the bike is parked
Whether you have any working key, a broken key or a key code
Photo ID and registration or title (we verify ownership before making a key)

Ducati ST2, ST3, ST4 and ST4S key FAQ

Does my Ducati ST2 have an immobilizer?

Early ST2s and ST4s use plain keys, according to the owner's manual that covers both. For 2002 and 2003 bikes, check for a red key or a Code Card, or send us the VIN and we will confirm.

What does the CODE light on my ST4S mean?

Per the manual, a brief flash at key-on means the key was recognized. If it stays on, the code was not recognized: switch off, try again, then try your other black key.

Can my pannier locks use the same key as the ignition?

Often, yes. Case locks can usually be rekeyed to match the bike. It depends on the make of the cases, so tell us what is fitted.

How many keys can an ST3 store?

The ST3 manual says Ducati Service can program new keys and reprogram the originals up to a total of 8. Keys left out of that session stop working.

The immobilizer system on this bike

Ducati Immobilizer: Red Key, Code Card, PIN and Lost KeysEvery keyed Ducati immobilizer reads a transponder in the key and only lets the engine start when the code matches one stored on the bike.

More Ducati models

Services for this bike

Adventure Pannier Lock Keys: SW-Motech, Touratech and GiviAluminum panniers from SW-Motech, Touratech and Givi use small removable lock cores sold in matched sets, so one key can run every lid latch and every rack mount.
Motorcycle Immobilizers Explained: HISS, KIPASS and MoreA motorcycle immobilizer is an anti-theft system that only lets the engine start when it recognizes a coded chip in the key or a paired fob.
Bought a Used Motorcycle With No Key? Here's What to DoA used or auction motorcycle without keys can usually get new ones, but plan on the full all-keys-lost process and bring the signed title or other transfer paperwork plus photo ID, since a locksmith or dealer has to tie you to the VIN.
Motorcycle Keys Stolen but the Bike Is Still There?If your motorcycle keys were stolen and the bike is still there, assume the thief may come back for it.

Where we come to you

Sources

Page last updated November 14, 2026.