The following functions are carried out by means of the electronic control unit:
1. Fuel injection control.
Various sensors determine the air pressure in the intake manifold, the crankshaft speed. Engine, oxygen content in the exhaust gases, coolant temperature, intake air temperature, atmospheric pressure, etc., and convert the information received into an electrical signal sent to the electronic control unit. Based on these signals, the electronic control unit determines the required amount of fuel and controls the injectors. The amount of fuel supplied is regulated by the duration of the raised position of the injector shut-off needle.
2. Ignition timing control.
The memory of the electronic control unit contains the values of the optimal ignition timing for all possible engine operating modes. Using the signals of various sensors that control the operating conditions of the engine, the electronic control unit generates impulses that control sparking at strictly defined points in time.
3. Idle speed control system.
The memory of the electronic control unit contains the data of the optimal idle speed that meets various conditions (e.g. coolant temperature, air conditioner on/off, etc.). The sensor signals are received by the electronic control unit, which controls the air flow through the bypass channel (besides the throttle) and regulates the idle speed according to the set value.
4. Diagnostics.
The electronic control unit warns of a malfunction or abnormal operation by means of a warning lamp "CHECK" on the instrument panel. The fault is identified in the form of a diagnostic code, which is stored by the electronic control unit. Diagnostic codes are discussed below.
4. Function "Fail-Safe" ("Get home")
In case of failure of any sensor, emergency operation is provided (to get to the nearest service station). At the same time, a warning light is displayed on the instrument panel "CHECK".