Electronic control unit — general information

The ECU is the central engine control unit. It receives information from sensors and controls the actuators, ensuring optimal engine performance. The ECU is located under the instrument panel console in the passenger compartment.

Attention! The ECU is a complex electronic device. During operation and maintenance of the vehicle, disassembly of the ECU is prohibited.

The ECU receives the following data from the sensors via the multi-pin connector:

• from starter terminal 50 - data on the start and end of the starter operation are received;
• from throttle potentiometer (located in throttle body) receives information about the position of the throttle valve at the moment. In this way, in particular, fuel cut-off control is carried out, since as long as the throttle valve is in the idle position and the speed remains unchanged, the flow of fuel to the engine is stopped. In addition, the fuel supply is turned off during engine braking and the working mixture is enriched when operating at full load;
• from hall sensor (located on the side of the cylinder head and driven by the camshaft) receives information about the frequency of rotation of the crankshaft of the engine. It provides turning off and on the electric current, due to which a spark is formed;
• from lambda probe (located in front of the exhaust system) receives information about the oxygen content in the exhaust gas at a given time;
• from mass air flow sensor information about the amount of air entering the engine is received;
• from coolant temperature sensor (located in the coolant pipe above the thermostat) receives information about the temperature of the coolant and serves to correct the ignition timing and injection time on a cold and hot engine. Based on the readings of this sensor, knock, exhaust gas recirculation and idle speed are adjusted;
• from two knock sensors (installed in the cylinder block) information is received about which of the cylinders tends to detonate (uncontrolled combustion of a combustible mixture). They allow the ECU to regulate fuel injection and ignition timing separately for each cylinder in a given bank and to synchronize the compression pulses. More information about them can be found in (see section 8).

Constantly receiving the information described above about the number of revolutions of the engine, the mode of operation of the engine and its temperature, the ECU calculates the injection duration, i.e. the duration of the opening of the injectors and produces an accurate dosage of the amount of injected fuel. The so-called universal characteristics are integrated into the control device, which contain information about all possible conditions and operating modes of the engine, based on which the exact choice of the amount of fuel, as well as the corresponding ignition timing, is carried out. If there is a fluctuation in intake air temperature or coolant temperature, an appropriate correction is made.