During operation, the ECU monitors the serviceability of all elements and circuits of the engine control system. Having detected a malfunction, the ECU switches the engine management system to the backup operating mode and turns on the engine malfunction indicator lamp located on the instrument panel. The engine will still be able to continue working (except in case of crankshaft position sensor failure), which allows you to get to the repair site under your own power. The ECU records the codes of detected faults into the random access memory (RAM).
Error codes are written and read in accordance with the OBD-II standard. To read error codes, an external diagnostic device, a scanner, must be connected to the engine management system.
For this purpose, the system has a connector for transmitting data from a sixteen-pin block. The block is installed on the left side of the instrument panel at the bottom.
There are devices (adapters) that allow you to connect a laptop to the diagnostic connector. To read diagnostic information, a special program is required.
There are also adapters that transmit information via wireless communication protocols Bluetooth or WiFi. From these adapters, information can be received on smartphones and tablets, for which special programs have been written. These programs allow you to read and display OBD-II standard trouble codes, various parameters of the vehicle and its systems, both in real time and over a certain period of time.
You can read the fault codes at a service center that has the necessary equipment.
Note: Checking the condition of the engine management system components is shown below in the relevant sections of the chapter "Engine Management System".