Do you ever wonder how our car’s engines are controlled? When all we need to do now is press a button to start the car. All of this is handled by your car’s engine control unit, commonly known as an ECU.

The Functions of the ECU

If you have seen older cars, you will know that they have way more things that the driver has to control, compared to modern cars. All of the different engine tuning settings, such as the air/fuel ratio, idle speeds, ignition timing, and variable valve timing etc. 

These calibrations which used to be manually controlled are now controlled by an electronic control unit, which reads data from various sensors embedded inside the car’s engine, which then goes through a microprocessor that adjusts to reach optimal operation.

For example, the engine control unit reads data from the oxygen sensor (O2 sensor), mostly located in the exhaust system, which compares the amount of oxygen in exhaust fumes with the amount of oxygen outside the vehicle. A car running rich will require more oxygen to combust, while a car running lean won’t use that much oxygen. The ECU will then use this data to adjust the air/fuel ratio fed into the engine to reach an optimal ratio for driving.

Modifying The ECU

Most factory ECU’s cannot be reprogrammed, for safety and other related reasons, which most people will probably not do. If you really want to modify your car’s ecu to bring out more performance or for other reasons, you will have to swap out the factory one out for a standalone ECU, which offers more customizability, or get a piggyback which alters data from the factory ECU.

Most ECU’s control more than just the engine of the car, so it can be dangerous if you modify the factory ECU, where you have a chance of stuff failing.

A faulty ECU can also result in your car running weird, as a result of maybe water damage, which is harmful to the ECU as it is a mini computer, which water can cause it to short circuit. ECU’s can be swapped out if they are faulty, and might be the reason for recurring issues on your car even if your car is perfect mechanically.