When your car won't start you may immediately by thinking of a list of things that could be wrong, from a dead battery to poor wiring and even to an empty fuel tank. While all of these can be the culprit, have you thought about whether or not your key could be the problem?

Most cars on the road today have what's called a transponder key, which is a small computer chip that communicates with the car when the key is inserted. If your key has a large casing on top of it that allows you to open the locks with the touch of a button, then your car has a transponder key. Note how this key could be the reason that your car won't start, and what to do about it.

1. The key battery is dead

The transponder key communicates with the car's engine as a safety measure; if someone attempts to start your car with anything other than this key, the engine won't turn over. This keeps thieves from starting the car by hotwiring it or using some type of tool in the ignition. However, like all computers, the transponder key needs energy to work; inside the housing is a small battery. If this battery goes dead, that signal or communication is lost, and the engine won't start.

The battery of your transponder key should be something to check, if you've ruled out mechanical issues with your car. If you try to start the engine and your car doesn't even click or try to turn over, the key's battery might be the culprit.

2. The key needs reprogramming

Like all computers, the chip inside your transponder key needs to be programmed so that your car's engine can communicate with it. If you've recently had new keys made or are using a spare key of any sort, your key may need to be programmed so it can communicate with your car's engine. To do this, find your car's owner's manual and look up the information about how to program your transponder key. In some cases reprogramming is just a matter of hitting certain buttons in a certain order. There may also be a reset button under the hood or dashboard of your car.

You can also try to disconnect the battery cables to your car for several minutes and then reattach these. In some cases this will allow the programming in your transponder key to reset the programming of the engine itself. If you cannot reprogramme the key yourself, call locksmiths like Night & Day Locksmiths that specialises in transponder keys.