Up until recently, ECU manufacturers made stand alone units for the control of perhaps engine and ABS systems. These units had data storage devices inside. These "chips" could be removed and read, then the data analysed. This data is not encoded, however when downloaded it is in a hexadecimal format and makes very little sense. Some companies started to appear who specialised in making sense of this data. Functions of small sections of this data was guessed at and then altered to see it's effect on the tuning of the car. This was not terribly satisfactory but sometimes the car went a little faster. In these early stages, there were very few cases where there was any real knowledge of what was happening within this ECU.
The situation now is actually worse than it was in the early days due to the complexity of the ECU's and the advances made in microprocessor design. These ECUs have many times more data & code than they used to. Analysis of this information is now very time consuming. With Japan leading the way in electronic development it is no surprise to learn that engine ECU's fitted to Japanese cars are some of the most advanced in design. The origin of this technology, and the sheer volume of units produced allows these companies to produce custom microprocessors, specifically fot the ECU design. This makes analysis of the data extremely hard, especially when the only data you can get is in Japanese !
As well as the ECUs containing far more code and data than they used to, access to the information is now far more difficult. Memory chips now tend to be integrated into the microprocessor itself. This means it is no longer possible to replace the memory chip as it was before. Some companies resorted to removal and replacement of the entire processor, but this is a time consuming (expensive) and unrealiable method - how would you like to remove and refit a 160 pin chip with pins that are hundredths of a millimetre thick ! Even when the chips are removed, it is often not possible to read and rewrite the data on them. ECU manufacturers can use complex encryption algorithms to stop the internal ECU information being accessed. Once the data is in the system there is no way to access it or to alter it due to the style of processor and the skill of the programmers.
The situation is more straightforward with European ECU technology. Most of the major car manufacturers use standard technology bought in from a specialist company, such as Bosche. This means that the information on how to program the units is far more accessible to aftermarket tuners.
Communicating with the ECU has become easier with the adoption of standard communication protocols . OBD-II is the industry standard format for On Board Diagnosis across all vehicle marques. In 1988, the Society of Automotive Engineers (SAE) set a standard connector plug and set of diagnostic test signals. The US Environmental Protection Agency adapted most of their standards from the SAE on-board diagnostic programs and recommendations. OBD-II is an expanded set of standards and practices developed by SAE and adopted by the EPA and CARB (California Air Resources Board) for implementation by January 1, 1996. However, OBD-II being a worldwide standard has it's limitations in terms of speed and functionality. However, it is a sophisticated fault code reading standard.
For mapping and data analysis purposes, OBD-II is next to useless. Since all new cars must support OBD-II, the standard is a lowest common denominator. The standard specifies that an OBD-II reader must not request data from the ECU at more than a certain rate, even if the ecu is capable of much higher speed. For this reason among others, car and ECU manufacturers choose to support OBD-II as a legal requirement, but use other, custom protocols for their programming and diagnostic functionality. What is required for optimum diagnostics and tuning is an advanced method of communicating with the ECU and transferring data at transfer rates which enable useful analysis.
This is where ECUTEK can help...