Description of the engine management system (Kalina 1119)

The engine management system switches the fuel pump on and off, controls the amount of air entering the engine cylinders, injects the required amount of fuel into the intake manifold, controls spark formation on the spark plugs, adjusts the ignition timing, regulates the idle speed of the crankshaft, and controls the electric fan of the engine cooling system.

Engine management system - electronic, with distributed phased fuel injection (that is, fuel is injected into the intake manifold of each cylinder in accordance with the engine's working cycle). The system consists of the following elements:

electronic control unit;

sensors:

• 1) crankshaft position sensor;
• 2) camshaft position sensor;
• 3) throttle position sensor;
• 4) knock sensor;
• 5) coolant temperature sensor;
• 6) mass air flow sensor;
• 7) vehicle speed sensor;
• 8) two oxygen concentration sensors;
• 9) Rough road sensor;
• 9) pressure sensor (for vehicles with air conditioning);

actuators:

• 1) main relay;
• 2) fuel pump relay;
• 3) injectors;
• 4) ignition coils;
• 5) idle speed controller;
• 6) cooling system electric fan relay;
• 7) Engine malfunction indicator light;
• 8) purge valve of the adsorber;

connecting wires;

diagnostic connector block.

The engine management system also integrates:

• speedometer;
• tachometer.

Note: Engine with decorative trim removed. The fuel injectors are mounted under the intake manifold pipes.

The main control element of the system is the electronic control unit (ECU), or, as it is often called, a controller with a built-in microprocessor. In essence, the ECU is a specialized mini-computer in which only one program is installed - engine control, and the sensors and actuators form the peripheral equipment of this computer. The block receives and analyzes signals from sensors. Based on the received data, the unit calculates control commands and issues them to the actuators. The unit has three types of memory*: read-only memory (ROM), random access memory (RAM), and programmable programmable memory (PROM).

ROM - non-volatile memory (that is, the information in the memory is retained when the power is turned off) and is a microcircuit ("chip")*. The ROM stores the calculation program and the data necessary for the calculation (engine parameters, transmission ratios and other characteristics). This information is individual for each vehicle modification.

* The design of the ECU may be changed by the manufacturer.

Warning! Unqualified reprogramming of the ROM may result in engine malfunctions, failure of engine management system components, and engine damage.

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 on the instrument panel. The engine will still be able to continue working (except in case of crankshaft position sensor failure, see below), which allows you to get to the repair site under your own power. The ECU records the codes of detected faults in RAM. The operational information that the ECU microprocessor uses in calculations is also stored there. When the battery is disconnected from the vehicle's electrical system, all information stored in RAM will be deleted.



The EPROM stores the codes of the car's anti-theft system (immobilizer). This type of memory is non-volatile. After activating the immobilizer, the ECU blocks the operation of the engine management system when attempting to start the engine without special electronic keys.



The ECU, immobilizer control unit, fuses and relays of the engine management system are located under the instrument panel console.

The crankshaft position sensor (CPS) is designed to generate signals by which the ECU synchronizes its operation with the engine's operating cycles. That is why this sensor is often called a synchronization sensor. The sensor operates on the principle of induction: when the crankshaft pulley teeth pass the sensor core, AC voltage pulses are generated in the sensor circuit. The frequency of pulses corresponds to the crankshaft rotation frequency. The teeth are located around the pulley circumference (6° apart). Two of them are spaced at an angular distance of 18°. This is done to form reference signals in the sensor circuit - a kind of reference points relative to which the ECU determines the position of the crankshaft - the top dead centers in the first/fourth and second/third cylinders. Engine operation with a faulty crankshaft position sensor is impossible. The crankshaft position sensor cannot be repaired; in case of malfunction, it is replaced as an assembly.





The camshaft position sensor (CPS) is designed to generate a signal by which the ECU determines the top dead center (TDC) of the piston of the first cylinder during the compression stroke. Sometimes this sensor is called a phase sensor. The sensor operates on the Hall effect. When a ring projection, fixed on the intake camshaft pulley, passes through a slot in the sensor end, the sensor sends an electrical signal to the ECU. If the DPRV fails, the electronic control unit switches the system to backup mode.

The camshaft position sensor is an electronic device that cannot be repaired. If the sensor is faulty, it should be replaced.





The knock sensor (DS) is piezoelectric and reacts to engine vibration. Based on the sensor signals, the ECU determines the moment of detonation during engine operation and adjusts the ignition timing accordingly. If the DD fails, the electronic control unit switches the system to backup operating mode.







Film type mass air flow sensor (MAF), installed between the air filter and the throttle valve. Based on the sensor signal, the ECU calculates the amount of air entering the engine cylinders. If the MAF sensor fails, the electronic control unit switches the system to backup mode.



The throttle position sensor (TPS) is mounted on the throttle body and is connected to the throttle shaft. The TPS is a variable resistor whose resistance depends on the throttle position angle. Based on the TPS signal, the electronic control unit determines the amount of throttle valve opening. If the TPS fails, the electronic control unit switches the system to backup mode.





The idle speed control valve (ISC) is a shut-off valve driven by a stepper motor. The idle speed control valve is installed on the throttle body. The ECU, by sending a controlled signal to the idle speed control valve, regulates the engine crankshaft speed at idle, when starting and warming up the engine.



The oxygen concentration sensor provides an output signal that the ECU uses to determine the oxygen concentration in the exhaust gases. Based on the data received, the ECU adjusts the amount of fuel injected into the engine cylinders, thereby maintaining the optimal proportion of the air-fuel mixture (this is necessary for the efficient operation of the catalytic converter). The oxygen concentration sensor's sensitive element is located in the exhaust gas flow (before the catalytic converter). The sensor can only operate when its sensitive element is heated to a temperature of at least 300°C. To reduce the warm-up time, a heating element is built into the sensor.



On vehicles that meet the requirements of the EURO III toxicity standards, a second oxygen concentration sensor is built into the exhaust system after the neutralizer.

Warning! The presence of lead and silicon compounds in the exhaust gases may cause the oxygen concentration sensor to fail. Therefore, the use of leaded petrol is not permitted. When repairing an engine, do not use a sealant with a high silicone content (silicon compounds), vapors of which can enter the cylinders through the crankcase ventilation system and then into the exhaust tract. You should use a sealant that is labeled as safe for use with the oxygen sensor.

The coolant temperature sensor (CTS) is a semiconductor device, a thermistor, the electrical resistance of which changes with changes in the ambient temperature. The coolant temperature sensor is installed in the thermostat housing. Based on the sensor resistance, the ECU evaluates the engine's thermal conditions. The obtained data are used to calculate most of the control commands for the engine control system elements, as well as to turn on the electric fan of the engine cooling system. If the coolant temperature sensor fails, the electronic control unit switches the system to backup mode.



The vehicle speed sensor is mounted on the gearbox. The operating principle of the sensor is based on the Hall effect. Based on the pulses generated by the sensor, the ECU calculates the speed of the car. The signal from the sensor also goes to the speedometer.



To prevent the ECU from detecting false faults in the ignition operation caused by sharp jolts of the power unit when the car is moving over uneven surfaces, a rough road sensor (RRS) is built into the system.



The engine uses four ignition coils. They are mounted directly on the spark plugs. This eliminates the reduction of spark power due to current leaks (this is possible when the insulation of high-voltage wires is damaged).



The engines use AU17DVRM spark plugs, where: A — thread M14x1.25;



U — hexagonal part of the body for a 16 mm key;

17 — heat rating;

D — threaded part length 19 mm, with a flat seating surface;

B — the protrusion of the thermal cone of the insulator beyond the end of the threaded part of the housing;

R - built-in resistor;

M - bimetallic central electrode.

The engine can be equipped with spark plugs of similar type from different manufacturers (see table 8.4.1, p. 71).

The nozzle is an electromagnetic needle valve, on the outlet pipe of which there is a sprayer with four calibrated holes. The injector opens on signal from the ECU, and fuel under pressure is injected directly into the inlet valve. The amount of fuel entering the cylinder is regulated by the opening time of the injector. The engine is equipped with one injector per cylinder.



The purge valve of the adsorber is installed on the air filter housing (for more details see. p. 57, "Power supply system").

The diagnostic connector block is designed to connect an external diagnostic device (for example, DST-2M) to the engine management system. The block is installed in the floor tunnel lining.