Self-diagnosis function
Each ECU has a self-diagnostic capability whereby the ECM constantly monitors signals from certain engine sensors and actuators and compares each signal to a table of programmed values. If the diagnostic software detects a malfunction, the electronic control module stores one or more trouble codes. DTCs will not be stored if there are no codes for individual part faults or if there are conditions not covered by the diagnostic software.
In the MPI system, the ECU generates 2-digit fault codes for reading with both a fault code reader and «manual» methods, through flash codes.
Limited mode
Our system uses the reduced operation mode function (a feature often referred to as emergency mode). When certain faults are identified (not all faults cause the start of the reduced operation mode), the electronic control module starts the emergency mode and will not be guided by the signals from the sensors, but by the programmed values. This allows the car to safely reach the place of diagnosis and / or repair. When the fault is cleared, the electronic control module will return to normal operation.
Ability to adapt or «learning»
The system also uses an adaptive function that modifies the basic programmed values for the most efficient operation under normal conditions and when engine parts are worn.
Control lamp of system of self-diagnostics
The vehicle is equipped with a self-diagnosis warning lamp located on the instrument panel. If the lamp lights up while the engine is running, this means that the electronic control unit has diagnosed a malfunction in the system. The test lamp can also be triggered to generate flash codes.
Location of the self-diagnosis plug
The self-diagnosis plug is located in the fuse box on the left or right side under the dash panel.
The self-diagnosis plug is designed to read flash codes, and to use a trouble code reader.