Getting to know the Engine Control Unit (ECU)

This week in our “Getting to Know” series, we take a look at what an Engine Control Unit (ECU) is and what it does.


What is an ECU?


The Engine Control Unit (ECU) is often described as the ‘brain’ of the engine. It is essentially made up of a computer, and switching and power management systems, and these are all housed in a very small case.


How does the Engine Control Unit (ECU) work?


The processor takes information from various sensors which are located throughout the engine. It analyses information such as temperature, the accelerator pedal angle, oxygen content in the burnt exhaust gases as well as other measurements. Using the data from the sensors, the ECU can then add the right quantity of fuel at just the right time to provide a good mix of economy, performance and emission control when on the road.


How can you tell if something is wrong with the ECU?


Some of the most common signs of a malfunctioning ECU include a permanently lit engine check light on the dashboard, irregular fuel consumption or not being able to start the car itself. With today’s modern vehicles, a mechanic can often run a diagnostics test to identify any fault codes originating from the Engine Control Unit’s memory.


Where can I find a garage to get my ECU repaired or replaced?


To find your local Motor Ombudsman-accredited franchised car dealership or independent garage to get your ECU repaired or replaced, visit The Motor Ombudsman’s online Garage Finder.


Image courtesy of Last News 24