Once a year, regardless of the mileage.
1. This check, while not strictly mandatory, is part of the routine vehicle maintenance procedures specified by the manufacturer. During the test, using special diagnostic equipment, the condition and serviceability of the engine management system are evaluated. The electronic reader is connected to a special diagnostic connector, which allows you to poll the memory of the electronic control unit (ECU) for fault codes.
2. Strictly speaking, the actual need for this test arises only if there is a suspicion of a malfunction.
3. Some of the rather serious violations of the engine management system may go unnoticed by the owner for a long time. In case of certain failures, the system simply switches to an emergency mode of operation, the decrease in the efficiency of the engine's output, in which sometimes it turns out to be almost imperceptible and manifests itself only during a cold start.