What is the engine control unit, or ECU, which is a system that we often hear the name of? What does the ECU do? What is the mission of the ECU? We will seek answers to such questions.
In old cars, everything was manually adjusted for the engine to work. For example, the idling of a carburetor engine was made by turning a screw. Or when a malfunction occurred in the car, the driver wouldn’t know until he gave symptoms. In fact, many people would stay on the road for this reason. However, with the developing computer technology, all the devices in our lives have started to have brains. So they became a computer system manageable. Our cars are now computerized. It is popularly called the brain. However, its technical name is known as “Engine Control Unit (ECU)”.
What Does the Engine Control Unit (ECU) Do?
In fact, today’s cars do not use ECU. Because while the ECU keeps track of the engine and its components, a separate system for the transmission, the TCS, is used. Instead, there is now a more advanced computer called a power control system (PCM) that controls the entire system on its own. However, since this system is still very new, most of the vehicles you see on the roads have an ECU system.
If we ask how the ECU works. The engine and vital parts of the car are equipped with sensors. These sensors are all connected to the ECU and have a working reference. For example, the ECU, which interprets data from the oxygen sensor, uses data from the O2 sensor to adjust the engine’s ignition and fuel delivery. If the signals from the sensor are less or more than they should be, the ECU interprets this as a malfunction. These signals are an electrical voltage. In other words, during programming, the lower value of this voltage can be 1.5 and the upper value can be 5 volts. If this voltage is lower or higher, there is an abnormal situation in that sensor and part. The ECU, which notices this, immediately warns the driver that there is a malfunction. The answer to the question of how to understand that a car has a brain is simple. If your vehicle has an engine malfunction light and it lights up, it means that the car has an engine control unit (ECU).
The ECU uses software called OBD-2 fault codes to indicate the source of the fault. Each sensor can have its own fault code or more. Thanks to the computer connected to the ECU, the source of the fault can be directly determined. The process of finding faults with the computer is called the diagnostic technique.
Source: What is an Electronik Control Unit (ECU) and What Does it Do?