Many cars today very much like the one you are driving now runs on at least two computers known as modules. The primary ones are the Engine Control Unit (ECU) and the Transmission Control Unit (TCU), although some cars have more computers installed in them. These computers are responsible for running important functions in a car, and a faulty module can bring a car completely to a stop. Like other computers you use, laptops, smart phones and other electronics, they have tendencies of developing bits of glitches from time to time.
Similar to how you reset your smart phones and laptops when they have glitches by turning them off and turning them back on, you can apply the same procedure to your car computers. To do this, remove one terminal connected to the battery head, preferably the negative terminal. Next, with the battery terminal removed, turn on the headlight. Of course the headlight won’t come on, but it will drain remaining current in the computer circuits. Leave it for a couple of minutes, turn the headlight off and reconnect the battery. This will help fix minor problems that can cost you a fortune at a mechanics’.