Today, most cars are controlled by computers!
The fuel injectors, the spark plugs, the steering system and more are all told when to fire and when to move by an onboard computer system.
If something's going wrong with your car or engine, your onboard computer can tell you about it; it will turn on a dashboard light, like "ABS
Brakes" or something less specific, like "Check Engine".
Some people try to disregard their Check Engine light. And some have even gone as far as disabling it and that could be a costly move!