No matter the season, though it is more common in winter, an engine that won't start is a very unfortunate situation. We're talking about a combustion engine here, of course, as electric vehicles have a completely different system.
There can be numerous reasons why your engine won’t start, but it often comes down to the ones we will describe below.
1. Dead Battery
Of course, the main reason your engine won't start is that the battery that powers the electrical circuits is depleted. It may also be at the end of its life, or the alternator may be having trouble charging it. If the battery light comes on, or if none of the electrical systems work (lights, radio, etc.), this is a bad sign. Try to jump-start the battery with your cables (and a good Samaritan's vehicle!). If nothing works, it will need to be replaced.
2. Faulty Ignition Switch
Is the battery working? Good! How about the electrical systems and headlights? Great! Now, does the engine run? If it still fails to start after few tries, the ignition switch may be the culprit. Simply put, there is no contact between the ignition system and the starter. Note: When the battery in the smart key is dead, it usually is enough to move the key fob closer to the button for it to work in cars with a push-start button.
3. Starter Problem
A faulty starter can also be the reason why your engine won't start. It is an electric motor connected to the battery that is used to start the engine when the key is turned in the ignition, or when the push-start button is pressed. If you hear a "ticking" sound when you try to start the engine, then the starter needs to be inspected or replaced.
4. Empty Tank or Bad Fuel
This happens more often than you might think! You may not have noticed the low fuel warning light was on and the tank is now empty, thus preventing the engine from starting. Another possibility is that you made the mistake of filling it with diesel fuel while your vehicle has a gasoline engine. In this case, the fuel system will need to be purged and cleaned.
5. Clogged Fuel Filter
Gasoline or diesel fuel cannot get to the engine and start it if the fuel filter is clogged. Many drivers neglect fuel filter maintenance. A fuel filter should be changed every 30,000 to 50,000 km, but it all depends on how old the car is and how much you use it.
Alas, there's little you can do yourself other than to jump-start the battery. If your engine won't start, you'll most likely need to call a tow truck and take your vehicle in for an inspection.