In the injection cars, there is a piece that is called ECU (Electronic Control – Engine Control Unit). ECU is a Micro Computer.
Like the other computers, this has a CPU, two permanent and temporary memories and has a plan. This piece is located inside the chamber of engine and in other words is brain of an injector car and can receive the information as live and simultaneous from various sensors including: around sensors of PRM, pressure sensor inside Manifold or MAP, Throttle Sensor or TPS, Coolant temperature sensor or CTS, air temperature sensor or ATS, oxygen or Lambda sensor, impact sensor and etc… and is responding to outputs such as: injectors, spark and more by analyze the moment situation of engine. Sensors are injection kits that if their number be more, the car works better. ECU determines the quality of car’s engine.
ECU evaluates the engine operating conditions based on those sensors that are attached to it and sends appropriate commands to injectors and spark plugs. Because the car’s dynamics is very complex and non-liner, so ECU designers put some tables with name of map into the memory of ECU which the amount of fuel injection, advance angle in each round, and engine load have been specified. Whatever the accuracy of these tables is been more, the ECU will be more accurate.
It should be noted that values of these tables directly depend on the geographic parameters of the engine, like the air temperatures and pressure.
All automotive electronic components have an output that in case of possible defects sends a signal to the central controller or ECU. After receiving the error signal, ECU piece reports it in the form of DTCs to the Diagnostic devices and turns on the Diagnostic lights to inform of driver. Error codes are reported to the central processor of ECU, as well as reports are offered to the Diagnostic device and repairman can easily see the defects of car.
One of the solutions of car repair by ECU:
The day discussion about the car’s ECU is tuning that generally is done in two ways:
- Reading the ECU data (map) and loading the new information that many companies had study about it, including: Autospeed, Tech TV, Chip Tuning, Eurochip, and etc… One of the drawbacks of this method is high dependence on ECU structure and by being complex the ECU hardware, reading and modifying the data is being difficult and more times is being impossible. The only solution for how to access to information is from the ECU manufacturer.
- Adding an external hardware to ECU is in order to the change of ECU parameters. Although this method is not economical, but it is not dependent on the type of ECU. One of the companies that are active in this field is the Dastek Company. This company is located in South Africa and has about 30 people staff. It has achieved remarkable success. The name of the Dastek Company Product is UNICHIP.
The operating principle of UNICHIP is such that reads the main sensors in an engine fuel injection (MAP, RPM) and then according to engine operating point, applies allowed values of these two sensors to the ECU, as the function of ECU gets better.
Statistics show that success of UNICHIP has been very high in this field: Of every 400 car, just a car may not be the optimal with UNICHIP, 80% of cars that are used in South Africa had installed UNICHIP in their cars. UNICHIP have been performed on more than 320 engine models from major automakers in world.