Engine control system - electronic, with distributed phased fuel injection (i.e. fuel is injected into the intake manifold of each cylinder according to the engine duty 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 meter (for vehicles with air conditioning);
executive devices:
- 1) main relay;
- 2) fuel pump relay;
- 3) nozzles;
- 4) ignition coils;
- 5) idle speed controller;
- 6) cooling fan relay;
- 7) engine malfunction indicator lamp;
- 8) adsorber purge valve;
connecting wires;
diagnostic socket.
The engine management system is also integrated:
- speedometer;
- tachometer.
Location of elements of the 16-valve engine control system in the engine compartment:
1 - rough road sensor;
2 - crankshaft position sensor;
3 - oxygen concentration sensor;
4 - idle speed controller and throttle position sensor;
5 - coolant temperature sensor (on the thermostat housing);
6 - installation location of the adsorber purge valve;
7 - mass air flow sensor;
8 - connecting block of the injector wiring harness;
9 - ignition coil of the fourth cylinder;
10 - ignition coil of the third cylinder;
11 - ignition coil of the second cylinder;
12 - ignition coil of the first cylinder;
13 - installation location of the camshaft position sensor.
Note. Engine with trim removed. The fuel injectors are installed under the pipes of the intake module.
The main control element of the system is the electronic control unit (ECU), or, as it is often called, a controller with an integrated microprocessor. In fact, an ECU is a specialized mini-computer in which only one program is installed - engine control, and sensors and actuators form the peripheral equipment of this computer. The unit receives and analyzes the sensor signals. Based on the received data, the block calculates control commands and issues them to the actuators. The unit has three types of memory*: ROM (ROM), random access memory (RAM) and flash memory (PROM).
ROM - non-volatile memory (that is, the information in the memory is retained when the power is turned off) and is a microchip («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 is subject to change by the manufacturer.
Warning! Unqualified reprogramming of the ROM can lead to malfunctions in the engine, failure of the elements of the engine control system, and damage to the engine.
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 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, see below), 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. It also stores operational information that the ECU microprocessor uses in calculations. When the battery is disconnected from the vehicle's on-board network, all information stored in RAM will be deleted.
The EEPROM stores codes for 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 trying to start the engine without special electronic keys.
Electronic control unit (ECU)
The ECU, immobilizer control unit, fuses and relays of the engine management system are located under the instrument panel console.
crankshaft position sensor (DPKV) is designed to generate signals by which the ECU synchronizes its work with the cycles of the engine's working process. Therefore, often this sensor is called a synchronization sensor. The operation of the sensor is based on the principle of induction - when the teeth of the crankshaft pulley pass by the sensor core, alternating current voltage pulses occur in the sensor circuit. The frequency of appearance of pulses corresponds to the frequency of rotation of the crankshaft. The teeth are located around the circumference of the pulley (after 6°). Two of them are separated from each other at an angular distance of 18°. This was done to form reference signals in the sensor circuit - original reference points, relative to which the ECU determines the position of the crankshaft - top dead centers in the first / fourth and second / third cylinders. Engine operation with a faulty crankshaft position sensor is not possible. The crankshaft position sensor cannot be repaired - in the event of a malfunction, it is replaced as an assembly.
crankshaft position sensor
Camshaft position sensor (DPRV) designed to generate a signal by which the ECU determines the top dead center (TDC) piston of the first cylinder during the compression stroke. Sometimes this sensor is called a phase sensor. The principle of operation of the sensor is based on the Hall effect. When the protrusion of the ring attached to the intake camshaft pulley passes through the slot in the end of the sensor, the sensor sends an electrical signal to the computer. In the event of a malfunction of the DPRV, the electronic control unit switches the system to a standby mode of operation.
The camshaft position sensor is an electronic device that cannot be repaired. If the sensor is defective, it must be replaced.
Camshaft position sensor
DPRV is installed in the rear protective cover of the timing belt
Knock sensor (DD) - piezoelectric, responds to engine vibration. Based on the signals from the sensor, the ECU determines the moment of detonation when the engine is running and, in accordance with this, corrects the ignition timing. In the event of a malfunction of the DD, the electronic control unit switches the system to a backup mode of operation.
Knock sensor
The knock sensor is mounted on the front wall of the cylinder block
Mass air flow sensor (DMRV) film type, installed between the air filter and the throttle valve. Based on the signal from the sensor, the ECU calculates the amount of air entering the engine cylinders. In the event of a malfunction of the DMRV, the electronic control unit switches the system to a standby mode of operation.
Mass air flow sensor
Throttle position sensor (TPS) mounted on the throttle body, and connected to the throttle shaft. TPS is a variable resistor whose resistance depends on the angle of the throttle valve. Based on the TPS signal, the electronic control unit determines the amount of throttle opening. In the event of a malfunction of the TPS, the electronic control unit switches the system to a backup mode of operation.
Throttle position sensor
idle speed controller (IAC) is a shut-off valve driven by a stepper motor. The IAC is mounted on the throttle body. The ECU, by supplying a controlled signal to the IAC, regulates the engine speed at idle, when starting and warming up the engine.
idle speed controller
The oxygen concentration sensor provides an output signal from which the ECU determines 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 sensitive element of the oxygen concentration sensor is located in the exhaust gas stream (before the catalytic converter). The operability of the sensor is possible only 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.
Oxygen concentration sensor:
1 - connecting block;
2 - wiring harness;
3 - sealing ring;
4 - sensitive element with holes for supplying exhaust gases.
On vehicles that meet the requirements of EURO III toxicity standards, a second oxygen concentration sensor is integrated into the exhaust gas system after the converter.
Warning! The presence of lead and silicon compounds in the exhaust gases can lead to failure of the oxygen concentration sensor. Therefore, the use of leaded gasoline is not allowed. When repairing the engine, do not use a sealant with a high content of silicone (silicon compounds), whose vapors can get through the crankcase ventilation system into the cylinders and further into the exhaust tract. Use a sealant that says on the packaging that it is safe for the oxygen sensor.
coolant temperature sensor (DTOZH) - a semiconductor device thermistor, the electrical resistance of which changes with changes in ambient temperature. DTOZH is installed in the thermostat housing. Based on the resistance of the sensor, the ECU evaluates the thermal regime of the engine. The data obtained are used in the calculation of most control commands for the elements of the engine control system, as well as for turning on the electric fan of the engine cooling system. In the event of a malfunction of the DTOZH, the electronic control unit switches the system to a backup mode of operation.
Coolant temperature sensor with copper o-ring
The vehicle speed sensor is installed on the gearbox. The principle of operation 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 is also sent to the speedometer.
Vehicle speed sensor
To prevent the ECU from detecting false malfunctions in the ignition operation caused by sharp jolts of the power unit when the car is moving over bumps, a rough road sensor is built into the system (DND).
The engine uses four ignition coils. They are mounted directly on the spark plugs. This eliminates the reduction in spark power due to current leakage (this is possible if the insulation of high-voltage wires is damaged).
Engine ignition coil 11194:
1 - conclusions for connecting the block of the wiring harness;
2 - eye for attaching the coil;
3 - rubber sealing ring;
4 - a tip for connection with a spark plug.
AU17DVRM spark plugs are used on engines, where: A - M14x1.25 thread;
Spark plug:
1 - side electrode;
2 - central electrode (in the thermal cone of the insulator);
3 - threaded part of the body;
4 - sealing ring;
5 - hexagonal part of the turnkey housing;
6 - insulator (It has a spark plug label on it);
7 - contact tip (removable, threaded).
U - hexagonal part of the body on a 16 mm turnkey basis;
17 - glow number;
D - length of the threaded part 19 mm, with a flat seating surface;
B - protrusion of the thermal cone of the insulator beyond the end face of the threaded part of the housing;
R - built-in resistor;
M - bimetallic central electrode.
Candles from different manufacturers of the same type can be installed on the engine (see table. 8.4.1, p. 71).
The nozzle is an electromagnetic needle valve, on the outlet pipe of which a sprayer with four calibrated holes is made. The injector opens on a signal from the ECU, while pressurized fuel is injected directly onto the intake valve. The amount of fuel entering the cylinder is controlled by the opening time of the injector. The engine has one injector for each cylinder.
Engine nozzle:
1 - atomizer;
2 - sealing rubber ring;
3 - terminals for connecting the wiring harness.
The canister purge valve is installed on the air filter housing (see p. 57, «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 lining of the floor tunnel.
Location of the diagnostic connector