ECU is an acronym for Electronic Control Unit, and not as many believe Engine Control Unit. Most modern vehicles are fitted with several ECUs; some will control safety devices, some traction control & drive systems and yes, at least one will control engine functionality. The correct term for this last ECU is the Engine ECU, which is the one that we are interested in.

So now that we know what an ECU is and that the ECU relevant to our question is an Engine ECU, how does it work?

The fundamentals of control engineering stipulate that to control something, you must first be able to monitor its function, then have the means to alter its behaviour that will, in turn, change the function you are monitoring.

Let’s now look at our Engine’s Electronic Control Unit (ECU). We can say that it monitors the engine’s functionality through various sensors that feed their information back to the ECU. Based on these inputs, the ECU then changes engine functionality under its control until the inputs from the sensors on the engine provide feedback that meets a set of pre-defined values.

Most if not all engine ECU’s are simply small computers with 4 or possibly 8-bit processors. Some have external read-only memory (ROM) where the control ‘software’ is stored; others have this ROM built into the processor (The Chip). There will also be some EEPROM or FLASH type memory to which data can be read and written. EEPROM/FLASH type memory is similar to that used in USB sticks and retains its data when power is removed. There will be some I/O interface electronics, basically the bits that allow the processor to get data from engine sensors and control some engine functions. That is the technical bit done with!

The sceptics amongst you will probably be asking:

“If you can give me all of this extra engine power, improved MPG and extra torque by remapping my engine’s ECU, then why do the manufacturers not do this?”

Here is your answer:

Vehicle manufacturing was probably one of the first industries in the world to adopt globalisation; having a small number of manufacturing bases that supplied various global markets. Each of these markets is identified by common sales and production cost factors and not geographic factors, although there is often a correlation between the two. A prime example is the European market or selling into Europe. Given that certain regulations relating to engine performance/emission control and the like are controlled by a central regulatory body, it is easy to see why vehicle manufacturers would produce a vehicle with an engine performance profile that meets all EU regulations but also meets all local EU country profiles in terms of emission control, service availability, fuel & road qualities. This then allows them to reduce production costs, which will equate to more profits.

By remapping your engine’s ECU, we can adjust the tuning to match conditions here in the UK while at the same time bias any changes to maximise acceleration & speed, improved torque (pulling power), improved MPG or any variation between these maximums to suit your own personal requirements.