Car key duplication: how to make the correct key copy [without and with immobilizer]

The course of a car’s life, it happens to have to do the so-called “key duplication” even if the term is not always literally correct. In fact, once it was trivial, to make a copy of the keys of your car from any hardware store. On average up to the mid-nineties you could easily duplicate the key, it was a matter of correctly replicating the part of the “blade” that unlocks the locks and the ignition switch. Today car keys, if there are any, are much more complex and duplicating an encrypted key in all its functions is not always feasible. Especially not cheap. However, there are useful alternatives.

Times and costs vary widely when a car key is lost or a copy is needed. Even some models have constraints, to issue to those who ask for a duplicate of the car key. Not only documents and certificates, but even the replacement of the entire series and the need for a vehicle stop for the procedure. Literally, due to the coding and some data written internally to the keys, it is a question of “adding” a new transponder (physically included in the key) to the immobilizer control unit of the car and not replicating.

Some control units do not accept new single keys but require the rewriting of the entire series, setting limits in case of extreme urgency, perhaps outside the home. The concept of the old duplicate therefore no longer applies to many modern cars. The regular procedure for providing additional keys to a car today normally requires the possession of a secret PIN, linked to the car and certification of legal ownership of the vehicle for which the addition of keys is requested. There is no need to report to the police, but it is always better to have and provide the operator with the old keys that you want to keep, together with the request for “duplicates” which are not duplicated, if they are additional keys.

It is true that many craftsmen or specialists in car keys can still supply duplicates, still intended as such, without going through dealers and the official network. The immobilizer control unit, if the duplicate is done in a workmanlike manner, recognizes the same copied key and takes it for granted. However, the internal transponders also need to be replicated and this becomes less and less possible over the years, albeit convenient in terms of cost.

The advice is to hear from both sources, in case of need for a “new” car key. Both what the manufacturer proposes, which can be additional supply, recoding, addition or replacement of some parts (eg code box or blocks). This is what allows an independent specialist to do, who maybe can actually duplicate the key of his car without the risk of errors, immobilizer blocks or other. Sometimes it may happen that for many cars it is still possible to buy, at a reduced price, compatible keys that are physically duplicated and then through OBD connection, with official or parallel diagnosis, are learned from the immobilizer control unit for the “software” part.

There is no fixed rule and, trivially, the more the cars are evolved and “richer”, the more expensive it becomes to redo a key. What still often remains today is the “mechanical key code” to duplicate or recode a copy of the key with the same metallic trace. Often these electronic codes or PINs, as mentioned, even if lost, can be requested (by paying) by the car owner through the company’s service network and used freely, with aftermarket equipment.

Some specialized hardware stores, equipped with this equipment, are still able today to satisfy the requests for a copy of car keys, guaranteeing lower prices than the parent company provides. They are customer choices, with various pros and cons. Such as disabling some control functions by modifying the electronic part, so that certain cars can be “free” from the immobilizer block and then make all the copied keys you want, without any limit and at ridiculously expensive costs as in the past.

It touches on technical and functional aspects, for which the owner of the vehicle is truly responsible. Above all, some interventions, if made during the warranty period, may affect its validity (eg use of compatible copied keys or replacement of parts related to start-up). How much does it cost to duplicate a car key or have additional keys? It depends, each car manufacturer has its own systems that are renewed over the years, adding complexity and often also costs. A car key today is also a remote control and personal data container, for premium cars. If the minimum costs of simple keys, replicable with reproduction of the transponder and the blade only, are a few tens of euros, in complex cases the figure is three zeros.