Lexus Key Replacement - Replacing a Remote Or Fob

The battery inside the key fob will eventually go out, whether you have a conventional lexus key cutting Key that operates the ignition, or an intelligent key for your car that starts by pressing a button. Replacing it is easy with using a paperclip. Pop the old battery out and insert the new one (refer to the manual for your owner to see which type of battery you need) and then secure it back in the correct position.

Keys

Lexus keys are not easy to replace and require a specialist locksmith for replacing car keys to make a functioning spare. Each Lexus key is equipped with an embedded microchip that must be programmed in order to communicate with the immobiliser system in your vehicle.

It requires a lot of time and special equipment for this procedure to be executed correctly. Each model has its own specific programming process. Replacing remotes or keys is a pricey task that should be left to professionals, unless you are equipped with the proper equipment and know-how.

Whether you have a conventional key that turns in the ignition barrel, [empty] or a smart key that starts your car at the click of the button they will both eventually need their batteries replaced. You can save money by doing it yourself, but it will require the use of a small Phillips screwdriver as well as a coin (a 20p piece is a good choice) and a paperclip. You will find two or three screws on the back of the fob for the key. Unscrew them, and keep them safe (they are small and easy to lose). Remove the fob, which will reveal an indentation with a circular pattern where the metal key will be. The battery can be removed with the paperclip, and then insert the new battery, making sure that it's properly inserted. Then, clip the outside of the key back to the fob.

Remotes

Lexus remotes and fobs can be difficult to replace and require locksmiths who are well-versed and have the proper tools. Certain models require the transponder in the key to be reprogrammed in order to function with the immobiliser system in the car. These chips are programmed by different methods, based on the model of Lexus. This is done by using a special device which sends a code chip to unlock the doors or start the engine.

Some Lexus models are built with a unit that combines the key head and the remote. They are much easier to replace because there is no chip that needs to be replaced. This kind of key is also a bit cheaper.

All fobs eventually lose their battery power, regardless of the kind of key. This can be a frustrating situation, but it's possible to get your Lexus back in operation with a bit of know-how. Refer to the owner's manual to determine what type of battery you require. Then, search for a replacement. Find a small hole on the inside of your fob. Insert the coin (20p works well) into the hole and twist. The fob should be revealed as a flat spot that you can make use of a paper clip to remove.

Then, pull the old battery out and insert the new one. Be sure the replacement battery is in the proper polarity. Finally, clip the inside of the fob back together and re-insert the metal key.

Transponder Chips

Nearly all new cars built since 1995 have transponder chips within the key head to disable the immobiliser system. The head of a key that is equipped with a transponder chip may be removed to reveal a metal L-shaped key. A transponder-chip replacement keys or fob is a multi-stage procedure. It involves cutting keys precisely and programming the chip to make it sync with the vehicle's immobiliser.

A transponder is an electronic chip that has Non-Volatile Memory (NVM) that contains a set of windings (very fine wire coiled around the tube) that look like the ones found in an electric motor. These windings form a coded signal that the car can read. If the code is correct it will allow the car to start.

There are two kinds of transponder chips. One is called the 80 bit and the other is known as a circle + (General Motors). The first kind is reusable, but must be unlocked with a special machine in order to work on another compatible vehicle. The latter is a bit more difficult, as the older ones are often broken and drilled or thrown away when key cases are replaced. However, they can be used with a service-key that doesn't require a battery.

Immobiliser Systems

An immobiliser system is an electronic security feature that stops thieves from starting your car. It works by sending an electronic signal from the vehicle to the key whenever you try to start it. The electronic chip inside your key then responds with a unique code which must match that of the vehicle to start. If the codes do not coincide, your engine will stop immediately to stop theft.

Modern smart keys and fobs have an embedded transponder chip that stores electronic security in a format that cannot be duplicated. When the key or fob are inserted in the ignition, they transmit this code to the ECU. The ECU compares this code with the one it has stored in its memory, and it activates both the fuel system and the ignition circuit if they are compatible. If the codes do not match, the engine will not start even in the event that the ignition circuit is short-circuited by a burglar.

Replacing a key or fob is a multi-stage process that involves accurate cutting of the new key blade, and programming it to connect with the immobiliser system of your vehicle. There are a variety of immobilisers used in different years and models and each needs its own unique programming procedure. We use Ross-Tech to ensure that the replacement key is programmed correctly. This will ensure the highest level of performance and security.