The advancements in engine control units (ECUs) over the last 40 years have played a large part in re-shaping the tuning and vehicle control landscape. Not only have developments in this field made contemporary racing and production engines more efficient and more tractable, but the modern ECU offers failsafes, accurate systems modelling, greater systems integration and a range of other features that require evermore focus and attention from the systems calibrator. What we used to call a tuner.

In this article, we look at some of the recent developments in ECUs that have broadened their range of applications, as well as some of today’s more intriguing calibration challenges.

Basically, the ECU consists of a processor that uses a pre-programmed map that monitors inputs and controls its outputs thousands of times per second, offering precise control of the fuel injection and ignition of a modern engine.

In slightly more detail, the ECU contains a printed circuit board (PCB), upon which microcontroller chips and the central processing unit (CPU) are mounted. The software is stored in flash memory. Thirty-odd years ago, a simple software update required replacing the chip, but advancements in flash memory made in the 1990s now allow for re-programming of the chip without altering the physical make up of the ECU.

Control centre

In addition to monitoring the position of the engine, firing of the ignition coils and fuel injectors, the ECU has taken on many other roles over the years. These days, it acts as a complete vehicle control unit. Various inputs are