An engine control unit enables the control of all processes around the combustion engine. This is important so that the engine can function optimally. Here you can find out how modern engine controls work and what they are made up of.

How does the engine control of a car work?

The engine management system in the car ensures the perfect interaction of all engine components. This makes it possible to achieve the necessary torque and power requirements under all operating conditions.

Basics of engine control

In earlier times, engine control exclusively concerned components such as the camshaft driven by a timing chain or the valves. Today, control is entirely electronic, with the engine control unit processing and passing on a great deal of information.

Functionality of control units

Control units such as

record numerous data, process them further and control various processes during engine operation. For example, combustion and the cleaning of exhaust gases are regulated by the engine control unit.

Sensors and actuators

Sensors and actuators are components that record information or implement commands. In the field of engine control, sensors have the function of sending various data and information on operating states to the engine control unit.

Exhaust gas standards and exhaust gas cleaning

The modern engine control system ensures that the engine runs perfectly. Thanks to the intelligent coordination of the operating processes, the engine also emits fewer exhaust gases. In conjunction with the exhaust gas purification system, the standards for the removal of exhaust gases are met.

Injection and ignition control

The engine control unit regulates the fuel injection and ignition processes. In this way, fuel is injected into the engine at the right time and in the right quantity. Air and fuel are also ignited at the right time.

Components of the engine control system of a car

The engine control system of modern vehicles consists of numerous components. The various components interact to allow effective control of the combustion engine.

Control unit for the engine

The engine control unit is the central unit of the engine control system. Modern control units work similar to computers with integrated microprocessors or microcontrollers. The engine control unit is located near the engine and usually has a metal housing.

Sensors such as temperature sensors, mass air flow sensors, pressure sensors

In order to control the engine functions effectively, numerous sensors are integrated into the engine control unit. These include sensors for measuring the engine temperature, as well as sensors for the inflow of air or the oil pressure.

Actuators such as injection valves and ignition coils

Various actuators implement commands from the engine control unit. In their design, they resemble small drives and take over functions such as fuel injection (injectors) or the regulation of fresh gases. Ignition coils provide the appropriate spark at the spark plugs.

Lambda sensor and catalytic converter

The lambda sensor measures the residual oxygen content in the exhaust gas and forwards this information to the engine control unit. The engine control unit then adjusts the ratio of fresh air to fuel. The catalytic converter reduces the pollutants in the exhaust gas.

Power supply and fuses

In order for engine controls to function reliably, they need a secure power supply. This is ensured by various parts of the vehicle’s electrical system. Fuses protect against a defect in the engine control unit in the event of a short circuit.

Signal processing and data transmission

Signals for engine control are transmitted both digitally and analogue and processed in the engine control unit. An exchange with other control units is possible via bus systems such as CAN bus.

What are the functions of the engine control unit?

The engine control unit is considered the most important component of engine control in the modern combustion engine. The device performs numerous functions around the engine and carefully processes every piece of information.

Injection and ignition control

Engine control via the engine control unit enables optimum interaction between injection and ignition. The fuel is injected into the intake tract or the cylinder at the right time and ignited.

Monitoring of engine and exhaust gas values

In addition to regulating the processes during engine operation, the engine control unit also monitors the removal of exhaust gases and compliance with exhaust gas requirements. Numerous values of the engine such as pressure and temperature during operation are also monitored.

Regulation of air and fuel supply

The engine control unit regulates the correct inflow of air into the intake tract, as well as the supply of fuel. In this way, fresh gases are available in the optimum ratio at all operating states of the engine.

Checking the lambda sensor

The engine control unit monitors the lambda sensor installed in the exhaust tract of the car. If components such as the lambda sensor are defective, modern engine control units issue a corresponding error message.

Protective functions such as emergency programme and fault diagnosis

If defective components in the combustion engine can lead to critical operating states, engine control systems protect the engine. For this purpose, the engine control system puts the engine into emergency running mode if necessary. In addition, the engine control unit enables fault diagnosis.

Adaptation functions

Newly installed parts such as sensors in the intake system or actuators often have to be taught-in first. The components can be taught to the existing engine control system in the vehicle via corresponding adaptation functions.

Spare parts for the engine control unit

All parts of the engine control unit can be defective at one time or another, so that they must be replaced. When buying and replacing spare parts for engine control units, there are a few points to bear in mind.

Things to know about buying spare parts for the engine control unit

When replacing components of the engine control unit, it is often necessary to teach the electronics after installation. Newly acquired components such as sensors do not necessarily have to be broken just because they do not work as desired right away.

Which parts can be bought new or used?

Almost all engine control components can be purchased both new and used. However, the purchase of used spare parts such as control units or sensors should be made from a reliable source. The functionality must be ensured.

How to obtain the correct components for the engine control unit

When selecting parts for engine controls, it is important to choose the exact parts that fit. Often the components differ depending on the version of the engines. Here it often helps to compare the part numbers of the components.

Control unit and programming during exchange

When changing engine control unit components, not only components have to be taught to the control unit, but mostly also the engine control units have to be taught to the car. Programming is therefore necessary so that the interaction of the newly acquired engine control unit with all parts of the car functions smoothly. The programming is carried out by specially equipped companies.