The engine control unit (ECU) is the "brain" of a modern combustion engine and can have up to 200 connections providing it with vehicle data via a number of sensors. Based on this data, the control unit calculates all important parameters to ensure that the engine runs at its optimum.

In electronic terms, it comprises elements that we are familiar with from a "normal" computer: a microprocessor, RAM memory, ROM memory and a flash EEPROM memory, as well as digital input and output interfaces.

Function

Input and output of engine data

In order to calculate how to accurately regulate an engine's operation, control units process a wide variety of sensor data , such as the fuel pressure, engine oil temperature, angle of the throttle valves or information from the lambda sensor. In addition, operating factors such as the angle of the accelerator pedal or the signal coming from the cruise control are incorporated into the calculations.

Using this data and taking pre-set maps for the engine power, fuel consumption and driving style into consideration, the control unit calculates essential factors such as the ignition timing, valve lift, amount of injected fuel or the throttle valve position.

The engine maps are provided by the manufacturer, and this is precisely where Wetterauer steps in and optimises their settings.