There can be several reasons why a car key suddenly stops starting the vehicle.
Now, let's skip any other mechanical reasons that the car might not be starting.
The problem could be related to the key itself, the transponder, or the immobiliser system of the car. In some cases, the physical key may still work in the lock while the vehicle no longer recognises the electronic part of the key.
Firstly, we would check the key to see if we can read the chip that's inside it.
Usually, chips that are in the form of a carbon chip rarely stop working. They usually get lost while opening the key. That would be, for example, the case with an Opel Astra G 2002 key.
In other cases, the immobiliser chip is in the form of an antenna coil on a board. In those cases, the coil itself might be broken and might need to be replaced.
A lot of car keys have this problem, like Peugeot and Citroën models from 2004–2015, and many more.
Now, if the key is alright, there might be a problem with the immobiliser system. This is pretty generic the way I'm explaining it, but unfortunately, I can't specify it more without knowing the exact vehicle and the problem you're experiencing.
Contact us with your vehicle's make, model, and year, and describe what happens when you try to start the car. This can help us determine what type of assistance may be required.
