Published On: Sat, Jul 19th, 2014

Keyless Entry: 9 Things You Need to Know About Transponder Chips

Transponder chips work with car immobilisers, sending signals to an engine management system, igniting the engine. Read more details about the technology below, learning what to do if you need a spare or when confronted with several vendors and options.

Keyless Entry Tips

Introduction to Market

TheEuropean Directive enforced the use of immobilisers in the mid 1990s. Electronic chips in car keys disarm a vehicle, rendering it immobile. Most models, sold after 1995, have an embedded immobiliser and matching chip in the key. Check for a red or blue tab at the top of your key or ask your chosen car dealership about your transponder chips.


Transponders, embedded in the heads of keys, respond to signals emitted by engine management systems. If a chip is inconsistent or nonresponsive to the engine system, the car will not start. A particular key may open doors to the car and the trunk but may not ignite the engine. The groove of a key has nothing to do with its transponder-embedded technology.


Transponders are not uniform; individual carmakers produce unique chips and matching transponders. On occasion, ask dealerships about changes taking place regarding evolving technologies and modifications of key fobs and transponders.

In some cases, a dealership, trying to ensure a purchase, will state there is no other alternative to fixing or replacing a transponder without their assistance. This is untrue in most cases.


Web Buys

Because two keys look similar, it does not guarantee they work the same. Transponders are programmed to work with specific automobiles. Once a given responder is dedicated to a specific vehicle, it cannot be modified to work with others. To avoid costly mistakes or a wasted time, buy additional key fobs from your car dealership or directly from car manufacturer.



Transponder technology is not cheap. Due to the needed tools, equipment, computer software, man hours, and resources, transponder chips are pricy. Calling a car locksmith in London for assistance when key locked in your car is a lot cheaper than losing a transponder-embedded key.

Cost per key depends on dealership, model, and manufacturer. Costs also vary depending on one’s location. Again, beware of Web or remote purchases – particular key models may not work with your car.


Not the Locks

Programming a transponder chip is not similar to programming lock buttons. Different circuits address respective areas of the car. Internet-ready instructions help programme keys for remote locking buttons but not a transponder chip.


Dealer or No Deal

You have options other than at your dealership. Often, dealerships charge higher prices; and third-party vendors can leverage vehicle and manufacturer information to offer an alternative to dealership prices.


Cut Corners

Don’t cut corners when it comes to finding replacement transponders and keys. As mentioned, transponders are programmed to work with specific key fobs and matching engine systems. Also, cheaply-made spare keys can ruin car locks and ignitions. In worst-case scenarios, a poorly made key warrants a new ignition system – very costly.



Manufacturers produce ‘programmable transponders,’ programmed into the car’s memory with diagnostic tools. A specific ‘code,’ written on them and linking transponders to a specific car and key set. ‘Cloneable’ transponders have no initial code yet emulate the criteria of programmable transponders, creating a perfect match to the original.

Sam Matthews has a mind suited to technicalities and mechanics. As an automotive engineer, he loves blogging about emerging ideas and technologies for making life on the road safer and more convenient.