Lexus Key Replacement - Replacing a Remote Or Fob

If you own a traditional Lexus key that turns on the ignition, or a smart key for your car, which starts with the push of a button, eventually the battery in your key will go out. 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 determine the type of battery you require) and then clip it back into the correct position.

Keys

Lexus keys aren't simple to replace and require a specialist locksmith for replacing car keys to make a working spare. This is due to the fact that every Lexus key is equipped with an embedded microchip that must be programmed to sync with your vehicle's immobiliser and if it's not, it'll not be able to start.

This process takes time and requires special equipment to perform correctly, and each model has a distinct method of programming. Replacing a lost or damaged key or fob is a costly job and one you should leave to professionals unless your have the proper tools and knowledge.

If you have a traditional key that turns on the ignition barrel or an electronic key that starts the car at the touch of one button they will both eventually need their batteries replaced. lexus car key can be done yourself, but you will need the smallest Phillips Screwdriver, a coin worth 20p and a paperclip. On the back of the fob you will see two or one screw, unscrew them and put them in a secure place (they're small and easily lost). Take the fob off, revealing an indentation that is circular where the key made of metal will be. Pop the battery out with the paperclip, and then insert the new battery, ensuring that it's inserted correctly. Then, clip the outside of the key back together.

Remotes

Lexus remotes and fobs aren't easy to replace and require locksmiths who are both skilled and possess the appropriate tools. Some models require the transponder in the key to be reprogrammed so that it can work with the immobiliser systems of the car. The Lexus models use different methods to program these chips. This is done using a special device that sends an electronic signal to the chip which matches the code used to unlock the doors and start the engine.

Certain Lexus cars are designed with a unit that combines the key head and remote. They are simpler to replace, since there is no separate chip required. This type of key is also cheaper.

Whatever the type of key any fob eventually runs out of battery power. It can be frustrating however with a little know-how you can get your Lexus up and running again. Refer to the owner's manual to determine which battery type you require. Then, find an alternative. Find a small opening on the inside of the fob. Insert an amount of money (20p works well) into the hole and twist. You should see a flat surface that you can remove with the help of a paperclip.

Next, pop the old battery away and then insert the new one. Be sure the replacement battery is in the correct orientation. Clip the inside of your fob and insert the key made of metal.

Transponder Chips

Nearly all new cars made since 1995 include transponder chips within the key head to disable the immobiliser system. If you've got a key with a chip inside, the head is covered with a plastic cover that can be taken off to reveal an L-shaped metal key. The process of getting a replacement key fob made with transponder chips is a multi-stage process that involves precise cutting of key replacements and programming the transponder chip to link up with the vehicle's immobiliser system.

Transponders are electronic chip equipped with Non-Volatile memory (NVM) that contains a set of windings (very fine wire coiled around tubes) which look similar to ones found in an electric motor. These windings form a coded signal for the car to 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 former can be reused but must be delocked by a special machine to be used in a compatible vehicle. The second is more difficult to use due to the fact that the old ones can be damaged, broken or taken away when key cases are changed. They are able to be salvaged however and then used to create a service key that doesn't need a battery to function.

Immobiliser Systems

An immobiliser is a digital security device that stops thieves from starting your car. It works by sending an electronic signal from the car to the key each time you try to start it. The electronic chip inside the key responds by transmitting a unique code that must match that of the vehicle in order for it to start. If the codes aren't compatible, the engine will shut down immediately, and stop theft of your vehicle.

Modern smart keys and fobs contain an embedded transponder that can store electronic security information in a format that can't be copied easily. When the key or fob are inserted into the ignition, they send this code to the ECU. The ECU analyzes this code in comparison to the one it has stored in its memory, and then activates both the fuel system as well as the ignition circuit if they are compatible. If the codes don't match, your engine will not start - even if someone tries to short-circuit the ignition circuit.


Replacing a key or fob is a multi-stage process that involves precise cutting of the new blade for the key and programming it to connect with your car's immobiliser system. Each immobiliser system is unique and has its own programming procedure. We use Ross-Tech to ensure that the replacement key is programmed correctly. This will provide you with maximum performance and security.