In our modern era cars, motorcycles and industrial vehicles functionality is mostly based on electronics components and sophisticated software. Vehicles are equipped with brakes anti-blocking systems (ABS), Electronic Stability Programs (ESP), Anti Slip Regulation (ASR), airbag, Brake Energy Regeneration, radar etc.

Each one of these systems is controlled through an electronic unit which interacts with all other vehicle’s systems and all interact with the engine control system, the electronic injection, which uses an electronic control unit called ECU (Engine Control Unit). Until about 15 years ago the ECU received engine signals (sensors, acceleration command, etc.) and on more sophisticated vehicles, the signals from the anti-skid system. In those systems, the signal was transmitted through a cable the data processed by the Engine Control Unit were relatively limited.

In the nineties, then, we started to see diesel cars equipped with electronic injection. In 1997 the quantum leap: Alfa Romeo came out with its 156 JTD model, equipped with the “Common Rail” system although the start of the direct injection “Common Rail” system on a pre-industrial basis, was developed at the beginning of the thirties of last century by the researchers of the Zürich polytechnic institute.

In parallel, the group VW-Audi developed the “Fuel Injection Pump” system. The nineties saw therefore the turning-point in the evolution of the vehicles injection systems. Indeed, in the last 15 years we have been experiencing a sudden evolution of these systems, which control an increasing number of information. Car manufacturers have developed, even for eight cycle engines, engine control systems and direct injection. The ECU which controls both a diesel or an eight cycle engine, sends “commands” to the engine after having received a large number of information coming from all the systems and sensors with which the car is equipped. Based on the information received, the ECU uses specific data between the mass of data available, found in the software part called “mapping”. “Mapping”, in informatics, refers to the process which localizes given tables inside a database. The database is usually found inside the “Eprom/EEprom”, or inside the Microprocessor of the ECU itself. The software found in the Eprom/EEprom contains the values of all the sensors as well as the injection and ignition mapping values, etc.

In modern ECU databases we can find more than just one mapping related to the injection, ignition, turbo pressure, Rail pressure and what have you. In this way, you can find ten or fifteen mappings related to ignition and advance, turbo pressure etc. The ECU does not use all these mappings but only some of them. These are determined by the utilization conditions and the country where the car is sold. Other parameters which affect the selection of the mappings are the following:

External temperature

Engine temperature

Exhaust gas temperature

Atmospheric and Barometric pressure

The type of fuel used

The engine load condition

On board information systems such as ASR, ESP, etc

Cleanliness of the anti-pollution systems (DPF)

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