Transponder Technology in Cars

Transponder technology is used in many security applications regarding access and is pretty much standard in most motor vehicles today.

How it works

A small transponder chip is embedded into your vehicle's key. When inserted into the ignition the chip is energised by a radio frequency sent from the ignition barrel. Once energised the chip emits a code which is received and sent to the vehicle's ECU (Electronic Control Unit), also known as the computer or brain. If the code is correct the immobiliser of the vehicle is then disabled and will allow the car to start. If not, the vehicle will remain immobilised. Depending on the immobiliser system this may be by cutting off voltage to the starter motor, the spark plugs, the fuel pump, or a combination or all three.

If you suspect your key's transponder chip may be faulty then always try the spare key/s. Another issue can also be with the transponder receiver in the ignition barrel - this should not be overlooked.

Where is the transponder chip?

If your vehicle's key has no opening parts you may think you don't have a chip in it - not true. As the transponder chip does not require a battery and is energised externally it can be embedded within the plastic mould of the key. On many remote control keys where the key can be opened the transponder chip can be accessed.