Introduction to ECU control principles and types in automotive electronics

Simply put, the ECU is the electronic device that controls all of the car's electronics. These functions range from fuel injection to cabin temperature to controlling brake and suspension adjustments. Some vehicles have multiple ECUs controlling different functions, while others have just one ECU that controls everything.

For vehicles with multiple electronic control units, they are divided according to the tasks they perform. Some of these types are as follows:

1.Engine electronic control module

The engine electronic control module (ECM) uses its sensors to ensure the amount of fuel and ignition timing required for the engine to achieve maximum power and economy. It controls the engine's fuel injection and ignition timing, and provides the best control instructions for other output devices.

2. Brake control system module

In vehicles equipped with an Anti-lock Braking System (ABS), the Body Control Module (BCM) ensures that the wheels do not slip and determines when to apply and release the brakes to ensure that the wheels do not lock.

3. Transmission Control Module

When used on an automatic vehicle, the TCM ensures you get the smoothest possible gear changes by evaluating engine speed and vehicle acceleration.

4. Remote communication control module

Another TCU with the same abbreviation ensures that the on-board services function properly. It controls the vehicle's satellite navigation, internet and telephone connections.

5. Suspension control module

In vehicles equipped with active suspension systems, the SCM ensures the correct ride height and makes optimal changes to the suspension depending on driving conditions.

How does ECU work?

The work of the ECU is actually not as complicated as people think. It is an electronic device with base numbers and parameters filled in its memory. Powered by multiple sensors around the vehicle, the ECU data can effectively manage and control the electronic system by issuing instructions to increase the output of the electronic system.

As an example of how an ECU controls something, we can look at how an airbag deploys during an accident.

There are sensors around the car called crash sensors that notify the ECU when a collision occurs. The ECU then measures the speed of the vehicle at the time of the accident and then uses the onboard memory to compare data on whether the airbag should be activated. If the data provides enough reason, the ECU will deploy the airbag. All of this happens in just a few milliseconds.

What happens if the ECU fails?

ECU failure is the worst thing that can happen to a car. The overall performance of the car will be affected, the fault light on the car dashboard will light up, fault codes are likely to appear, causing the car to jitter at idle speed, stall easily while driving, and have poor acceleration.

What happens if the ECU freezes

If the ECU is dead, then the car won't start. The ECU controls the engine ignition, so a dead ECU won't start the car at all. Other functions won't work well either, but frankly, if the engine is dead, the other functions don't matter.