Description of the engine adjustment system (with manual transmission)

The engine control system has a large number of sensors, switches, solenoid valves, as well as an electronic EEC engine control module (A15), which regulates fuel access, exhaust gas recirculation, ignition operation, engine idling, fuel evaporation to the atmosphere and transmission operation.

Supply voltage

To terminal 1 of the EEC module (A15) voltage is constantly applied to save the memorized information. When the ignition is switched on, the ignition coil, EEC module relay (K31), HEGO sensor (Lambda probe, B3) get stress. All other elements of the engine control system are supplied with voltage through the relay of the EEC module (K31). Terminals 37 and 57 of the EEC module (A15) receive current from the EEC module relay (K31) via solder joint S55.

Ignition

For vehicles with manual transmission, the ignition system is integrated into the EEC module (A 15). Via terminals 58 and 59 of the EEC module (A15) the ignition processor controls the ignition coil (T2) and spark plugs.

Fuel pump

Fuel pump relay (K4) receives voltage from the EEC module relay (K31) and controlled from terminal 22 of the EEC module (A15). Terminal 8 of the EEC module (A15) used as a fuel pump control input. Current flows to the impulse switch (N61), which, in the event of an accident, turns off the fuel pump in the fuel tank (A31). The fuel pump is always on during normal operation and maintains system pressure even when the engine is switched off.

Power steering pressure switch

Power steering pressure switch (N96) at high pressure sends a signal to terminal 28 of the EEC module (A15). With high pressure in the power steering, the EEC module (A15) increases idle speed.

Engine cooling

Engine ventilation relay (K45) and motor fan motor (M37) controlled from terminal 13 of the EEC module (A15). In a car with air conditioning fan motor (M37) additionally controlled from terminal 31 of the EEC module (A15) and from double pressure switch (N76).

Board computer module

The on-board computer receives the fuel consumption value from terminal 34 of the EEC module (A15), as a result of this, the value of the indication of fuel consumption is calculated, and the distance that can be traveled before the end of the fuel in the fuel tank is displayed for the driver.

Air conditioning compressor adjustment

A/C Full Load Relay (WOT, K32) triggered if terminal 54 of the EEC module (A 15) connects to "mass". This causes the A/C compressor to shut off and the engine load is reduced.

Voltage applied to terminal 10 of the EEC module (A15), if the compressor switch is closed (N75). Based on this information, engine load and engine idle are calculated.

Fuel matching (octane adjustment)

Via terminal 42 of the EEC module (A15) the voltage difference is measured at the octane adjustment connector (R6), and this information is used to change the ignition timing.

Tachometer

Tachometer located on the dashboard (AZO combined instrument), connected to terminal 4 of the EEC module (A15).

Connection with "weight" and diagnostics

Terminals 17 and 48 of the module are connected to the EEC diagnostic plug (STAR). Terminals 18 and 19 of the module are connected to the EEC diagnostic plug (DCL). Terminals 16, 40 and 60 are connected to "weight" G1 and terminal 20 is connected to "weight" G19.

Magnetic valve

Magnetic injection valves (Y35, Y36 and Y38) supplied with voltage via the relay of the EEC module (K31). Each of the four injection solenoid valves is controlled continuously and individually from terminals 58, 59, 39 and 35 of the EEC module (A15). Injection quantity, i.e. the duration of the input signal is determined by the temperature, load and engine speed, as well as the composition of the exhaust gases. The longer the pulse duration, the greater the amount of injected fuel.

Idle speed control valve (Y13) receives the distribution voltage via the relay of the EEC module (K31). EEC module (A15) compares the stored nominal engine idle speed with the true idle speed and controls the idle speed control valve (Y13) via terminal 21. Idle air control valve (Y13) changes the amount of air entering the engine through the auxiliary air valve.

Magnetic valve cleaning through activated carbon filter (Y1) used to open and close the activated carbon chamber. The valve opens when terminal 11 of the EEC module (A15) connects to "mass". The fuel mixture can then be injected into the engine and burned there.

Air control solenoid valve (Y34) controlled by terminal 14 st of the EEC module (A15). The solenoid valve cuts off air to the exhaust device while the HEGO sensor (Lambda probe, VZ) will not reach its operating temperature, under certain conditions (high lower suction pressure, high load).

EVR/EGR solenoid valve (Exhaust solenoid valve, Y33) controls the amount of exhaust gases recirculated to the intake manifold. Valve actuated by vacuum and controlled from terminal 33 of the EEC module (A15). The EGR system does not function in traction mode or at full load.

Sensors

Terminal 46 of the EEC module (A15) used as "masses" for the following sensors: exhaust gas pressure conversion sensor (B40),throttle position sensor (AT 8), HEGO-sensor (Lambda probe, VZ), coolant temperature sensor (AT 10), camshaft position sensor (B41), intake air temperature sensor (AT 5), switch position sensor (B28), turbine speed sensor (B44) and transmission oil temperature sensor (A40).

Exhaust pressure transducer sensor (B40) and throttle position sensor (AT 8) receive 5 V from terminal 26 of the EEC module (A15).

Exhaust pressure transducer sensor (B40) measures the pressure difference between the incoming exhaust gases and sends a signal to terminal 27 of the EEC module (A15). The sensor is part of the EGR system.

Throttle position sensor (AT 8) consists of a throttle mounted potentiometer that sends a signal to terminal 47 of the EEC module (A15). With this signal, the module can calculate the throttle position (idling, partial or full load) and thus fuel access.

HEGO sensor (Lambda probe, VZ) measures the amount of oxygen in the exhaust gas. The pulse signal is sent from the HEGO sensor (Lambda probe, VZ) to terminal 44 of the EEC module (A15). Thanks to this, the EEC module can adjust the fuel-air mixture for the perfect operation of the catalyst.

Engine coolant temperature sensor (AT 10) (temperature dependent resistance) receives input voltage from terminal 7 of the EEC module (A15). The sensor informs the EEC module (A15) about the operating temperature of the engine, which is necessary to calculate the amount of incoming fuel.


Camshaft Position Sensor (B41) through terminal 24 informs the EEC module about the initial position of the first cylinder. This information is needed to open the injection valves in the correct sequence.

intake air temperature sensor (AT 5) sends a signal proportional to the intake air temperature to terminal 25 of the EEC module. This information is used to calculate the amount of incoming fuel.

Speed sensor (VSS) (AT 11) sends to terminal 3 of the EEC module (A15) a meander-shaped signal whose frequency is proportional to the speed of the vehicle.

Air quantity meter (B42) measures the amount of air that enters the engine through the air filter. This information is then sent to terminals 9 and 50 of the EEC module (A15) and is used to calculate the amount of incoming fuel.

crankshaft position sensor (B43) transmits the crankshaft position signal to terminals 5 and 6 of the DIS module (A23). This information is used to properly control the timing of the injector valves when starting the engine.