How an Engine Control Unit Affects the Car Performance? Check ECU with InCarDoc!

To dwell deeper, let's start from the basis

When our team wrote about car diagnostics and error codes, we repeatedly mentioned the term ECU. So, what is ECU?

An Electronic Control Unit (ECU) is an embedded system that controls one or more of the electrical systems or subsystems in a transport vehicle. The ECU is a part of an engine management system that allows car-owners to control vehicle internal processes. The ECU processes the amount of data with multiple operations to achieve maximum performance. This unit helps to control major parts of the engine and sensors, manage speed, affects the engine performance of a fuel injection system etc.

How does this component work?

The ECU meaning for car is a key to its functionality. The first control unit was implemented to Cadillac Seville in 1978 for a digital fuel injection system. A few years later, the first on-board diagnostic system (OBD) was introduced, and only between 80s and 90s the ECUs became widely used. For modern vehicles, ECU meaning can be compared with the brain of a car, and the engine with a heart.

The ECU continuously collects data from various sensors located throughout the engine and other vehicle components. Sensors collect information about the current state of the systems: engine speed and speed, throttle position, crankshaft position, collisions and deploys airbags, climate control and driver assistance features etc. The list of "what does ECU stand for" can be very long for modern cars.

The ECU operation sequence is:1. Input – Sensing the Environment → it collects real-time data from sensors & modules. → 2. Processing – Making Decisions → The ECU's internal processor evaluates all inputs. → it runs preloaded software → it determines the correct output signals → it gathers records and DTC → 3. Output – Acting on the Engine → the ECU controls actuators and systems with high precision →4. Power Management – Delivering Energy → it manages internal and external power delivery. Vehicle ECU is a computer responsible for all functionality.

What is the ECU in a car: pay attention to head features

The key job of the unit is to ensure reliable engine performance. Based on the collected data on engine speed and temperature, this unit controls fuel injection. The ECU adjusts the spark plug ignition and maximises engine power, ensuring that the engine is stable. Another equally important function of the control unit is diagnostic. This unit detects and reports malfunctions or failures of systems or sensors in the car.

All processes are aimed at reducing emissions from fuel combustion in one way or another. If you simply answer the question: ‘What does the ECU control?’, the answer is everything, especially when it comes to electric cars.

What does ECU do for diagnostics

Earlier, we mentioned the diagnostic functions of the car's control unit. The inCarDoc app enables users worldwide to check ECU in a few seconds with all internal processes, which achieve and deliver good performance and operation of all parts and systems of the car.

Drivers get information about the following engine parameters in real time:

✔ Engine speed
✔ Engine load
✔ Coolant temperature
✔ Fuelling system condition
✔ Vehicle speed
✔ Air pressure
✔ Ignition advance
✔ Intake air temperature
✔ Mass airflow
✔ Throttle Position
✔ Lambda probe (engine mode correction)
✔ Fuel pressure

What does engine control system mean for fuel economy?

The inCarDoc app is a state-of-the-art DTC scanner, and its advanced PRO version offers an economiser function to control fuel consumption. In addition to the previously mentioned functions, the vehicle's electronic control unit also monitors and regulates processes such as exhaust gas recirculation (EGR) and catalytic converter to reduce emissions and comply with environmental regulations.

DTC and ECU

Now, when the engine ECU meaning is clear, we will concentrate on diagnostic trouble codes. The ECU stores fault codes that indicate faults detected by the computer. There are General (approximately 10,000) and manufacturer codes.  You can learn more about codes in our other article.  However, these codes are stored in the ECU's memory, and in order for the car owner to find out about them, he or she needs to perform diagnostics using special software and an adapter.

In this section, we want to focus on those error codes that are directly related to the electronic control unit — also called the Powertrain Control Module (PCM) — are typically:

• Indicate internal faults in the ECU/PCM itself (hardware or firmware issues). DTC from P601 to P0606. 

• Signal communication issues with the ECU (loosing connection, CAN or LAN issues). It covers DTC from U0100, U0101, U0300 and some OEM codes.

• Refer to sensors or actuators that are directly managed by the ECU. There are a plenty of codes that point to sensors' failure.

Problem-solving

To resolve PCM errors, you will need to consult a specialist to help you. In some cases, the unit may need to be replaced or reprogrammed. But this is rare, so it's important to just have your car checked once every year or two.

We hope we have answered the questions what is a car ECU and how does an ECU work. Undoubtedly, for a modern car, this is everything, and without this unit, you will not be able to start the car.