What is the Engine Control Unit (ECU)?
The ECU could be described as your vehicle’s ‘brain’, it contains a processor, complicated electronic circuits and software developed to make your engine run.
The ECU is handed information from sensors installed on various parts of the engine. It analyses this information such as temperatures, accelerator pedal position, oxygen content in the exhaust gases, as well as many other parameters. Using the information from these sensors it can then tell the injectors right quantity of fuel to supply and at the right time in each cylinder to provide optimum performance and efficiency in all driving conditions and scenarios, from parking to pulling away & overtaking.
What is ECU Remapping?
When a manufacturer releases a car, it is then sold in countries all over the world. Across these different parts of the world there are some extreme differences in the conditions a vehicle is subjected to, including sub-standard fuel qualities, extremely cold (and hot) temperatures, altitude, differing emission laws and even the possibility that vehicle may not be serviced in line with the manufacturer recommendations.
Remember we said the ECU contains software, this software is often called the engine/ECU maps, the maps on your vehicles ECU contain “tables” of information that tell it what to do with the information it received from all the sensors. Instead of developing a different map for a vehicle to be released in different countries, the manufacturer will instead focus on producing a robust software that is suitable for vehicles being used everywhere. However to do this they have to compromise on things like engine performance and efficiency slightly, in order for the engine to work correct in all the differing conditions we mentioned above.