188.8.131.52.1. Diagnostics and adjustment
The electronic control system of the engine consists of an electronic control unit and the following sensors:
– the potentiometer of a butterfly valve – informs an electronic control unit on the provision of a butterfly valve and speed of closing / opening of a butterfly valve;
– the sensor of temperature of cooling liquid – informs the control unit on engine temperature;
– the air stream sensor – informs the control unit on quantity and air temperature, passing through the inlet air duct;
– the sensor of an angle of rotation of a bent shaft (it is installed in the ignition distributor) – informs the control unit on the speed of operation of the engine and the provision of a bent shaft;
– the sensor of speed of the movement of the car (it is established in a speedometer) – informs the control unit on the speed of the movement of the car;
– the switch in system of strengthening of steering and the switch in the air conditioning system (if it is established) – inform the control unit on inclusion of these systems in order that the control unit could adjust the speed of idling of the engine for compensation of additional load of the engine from these systems;
– the sensor of exhaust gases (only on models with the catalytic converter) – sends to the control unit information on the content of oxygen in exhaust gases.
Signals from all these sensors are analyzed by an electronic control unit. On the basis of this information the electronic control unit regulates work of fuel injectors (changing duration of impulses – the period of time during which injectors are open – in order that richer or poor fuel mix, in dependence because turned out that is necessary). The composition of fuel mix and speed of idling of the engine constantly change an electronic control unit to provide optimum start of the engine (at cold or hot start), warming up of the engine, single operation of the engine, the best operation of the engine at the movement on the highway and at a sharp set of speed.
The engine electronic control unit also completely controls the speed of operation of the engine in the idling mode via the additional valve of air supply. This valve which is installed on the case of a butterfly valve (model with the 1,6 liters engine) or an inlet collector (model with the 2,0 liters engine) controls opening of the air channel which passes by a butterfly valve. When the butterfly valve is closed, the electronic control unit controls opening of the valve which regulates amount of the air passing through the channel of the case of a butterfly valve and, thus, the speed of operation of the engine in the idling mode is controlled.
On models with the 1,6 liters engine the case of a butterfly valve has the device which can independently increase the speed of operation of the engine in the idling mode when the engine gets warm. This function is controlled by the temperature valve. When the engine cold, the wax capsule in the valve (the valve is installed in the case of a butterfly valve) is small, and the cam of bystry idling holds a butterfly valve of a little slightly opened. When the engine gets warm, the wax capsule extends, lifting a valve plunger up, it, in turn, turns a cam of bystry idling in required position.
On models with the 2,0 liters engine increase in speed of idling is controlled by the air supply adjustment valve which consists of a bimetallic spring and the gate. When the engine cold, the bimetallic spring holds the gate of open. Air passes through the valve that increases intake of air in an inlet collector. When the engine works, on a bimetallic spring of the valve tension which gradually increases its temperature moves. When temperature increases, the bimetallic spring is deformed and closes the gate, stopping additional air supply to the engine.
On all models, also, on the case of a butterfly valve the electromagnetic valve of increase in speed of operation of the engine in the mode of idling which is controlled by an electronic control unit is installed. The electromagnetic valve controls opening of the air channel which passes by a butterfly valve, and is used for increase in speed of operation of the engine when systems of strengthening of steering or the conditioner are included.
On some models the valve can be installed, but will not function.
On models with the catalytic converter the electronic control unit also controls system of production of the fulfilled gases and the control system behind release of vapors of fuel which are described in the corresponding chapter.
If the signals received by an electronic control unit from sensors go beyond admissible limits or will not be coordinated with each other, the electronic control unit switches over works to protected mode. In this case, the electronic control unit ignores the wrong signals of the sensor and takes a certain preset value for a sensor signal that will allow the engine to work, though with smaller efficiency. If the electronic control unit passes into protected mode of work, on an instrument guard the alarm bulb lights up and the corresponding code of malfunction is brought in memory of an electronic control unit.
If the alarm bulb lights up, it is necessary to address experts as soon as possible. In repair shop full diagnostics of a control system of the engine by means of the electronic diagnostic equipment which just needs to be connected to the diagnostic socket can be carried out.
The engine electronic control unit also has the self-diagnostics mode which the motorist can use. For obtaining more detailed information of cm. subsection 184.108.40.206.