During operation, the ECU monitors the health of all elements and circuits of the engine management system. Having detected a malfunction, the ECU puts the engine management system into standby mode and turns on the engine malfunction indicator lamp located on the instrument panel. The engine will then be able to continue running (except in the case of a malfunction of the crankshaft position sensor), which allows you to get to the place of repair on your own. The ECU writes the codes of the detected faults to the RAM (RAM).
Fault codes are written and read in accordance with the OBD-II standard. To read fault codes, an external diagnostic device, a scanner, must be connected to the engine management system.
To do this, the system has a connector for data transmission from a sixteen-pin block. The block is established in the left part of the panel of devices from below.
There are devices (adapters), which allow you to connect a laptop to the diagnostic connector. A special program is required to read the diagnostic information.
There are also adapters that transmit information via Bluetooth or WiFi wireless protocols. 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 trouble codes, various parameters of the car and its systems, both in real time and for a certain period of time.
You can read fault codes at a service center that has the necessary equipment.
Comment. Checking the condition of the elements of the engine management system is shown later in the relevant sections of the chapter «Engine management system».