The bonnet of a car is opened to determine if there is anything wrong with the engine. Firstly, the radiator water is checked. If the radiator water is below the minimum indicator level, it is refilled. Otherwise it is ignored and the engine oil is checked instead. If the oil is dirty, the engine oil is changed. Next, the car battery indicator is checked to identify the condition of the battery. If the battery indicator indicates low, the battery is replaced with a new battery. Finally, the car is started. If the car starts successfully, the process of repairing cars ends. However, if the car cannot start, the whole process of repairing is repeated.