Contents: Ignition system ↧ Crankshaft position sensor (CPS) ↧ Camshaft Position Sensor (CMP) ↧ Idle speed control valve ↧ Fuel injection system ↧ Fuel Evaporative Recovery System ↧ Crankcase ventilation system ↧ Knock sensor ↧ Technical specifications ↧
Ignition system
The process of supplying a spark to the spark plugs is controlled by the electronic engine management system (further ECU). To determine the ignition timing, the ECM uses the following information: crankshaft speed, crankshaft position, coolant temperature, intake air temperature, intake manifold pressure, atmospheric pressure. The ignition system sends a pulse to the cylinders in pairs (1st and 4th, 2nd and 3rd). The ignition coil is a non-serviceable element and cannot be repaired.
Crankshaft position sensor (CPS)
The CKR consists of a Hall sensor and a phonic wheel mounted on the crankshaft. The phonic wheel has 58 grooves around its circumference, one of which is wider than the others. When the wide groove and the Hall sensor coincide, the CKR produces a synchronizing pulse, which is the initial one for determining the position of the crankshaft.
Camshaft Position Sensor (CMP)
The operating principle of the SMP is similar to the operating principle of the crankshaft position sensor. The ECM uses the SMP to determine the moment of fuel injection and to recognize the strokes in the engine cylinders. If the sensor is faulty, the synchronization of the fuel injectors is carried out in the calculated mode according to the signals from the crankshaft position sensor.
Idle speed control valve
The ECU controls the idle speed control valve and, depending on the conditions, regulates the engine crankshaft speed at idle.
Fuel injection system
Fuel injection is carried out using injectors installed in the intake manifold, one for each cylinder. The ECM regulates the amount of fuel supplied based on information received from the manifold pressure sensor (MAP) and oxygen sensors (H02S). With an optimal air-fuel mixture composition, the best conditions for the operation of the engine and the catalytic converter are achieved.
Start mode
When the ignition is turned on, the ECM, based on information received from the coolant temperature sensor and the throttle position sensor, regulates the composition of the air-fuel mixture to start the engine. The ratio changes from 1.5:1 at -36°C to 14.7:1 at 96°C.
Driving mode
While driving, the engine operates according to one of two programs: open circuit, closed circuit.
Open circuit
The program is activated when the engine is started and the crankshaft speed is less than 400 rpm. The ECM does not take into account information from the oxygen sensors and is guided only by the pressure sensor in the intake manifold and the coolant temperature sensor.
Closed loop
The program is activated if the temperature of the oxygen sensors and/or coolant temperature sensor approaches the value set in the program, or after the programmed time has elapsed. The air-fuel ratio is maintained at 14.7:1.
Acceleration mode
As the vehicle accelerates, the ECM increases the amount of fuel supplied depending on the throttle position.
Braking mode
When braking, the ECM reduces the amount of fuel supplied depending on the position of the throttle valve. When the throttle valve is fully released and the engine speed is more than 1200 rpm, the fuel supply is temporarily completely cut off (forced idle mode).
Fuel Evaporative Recovery System
The system prevents fumes from the fuel tank from entering the atmosphere during refueling and vehicle operation. Fuel fumes enter the adsorber, where they accumulate and are retained for some time. The adsorber is filled with granulated activated carbon. The fumes are disposed of by burning them in the engine. The adsorber is purged by an electromagnetic valve. The process is controlled by the ECU.
A faulty purge valve or damaged canister may cause the engine to run rough or stall.
Crankcase ventilation system
Clean air is forced into the engine crankcase through the air filter, which forces toxic crankcase gases into the intake manifold. Thus, the gas burns during engine operation.
Failure of system elements may result in unstable engine operation or engine shutdown.
Knock sensor
The sensor uses a piezoelectric element to detect and convert vibration from fuel detonation into an electrical signal that is sent to the ECM. Based on the signal value, the ECM sets the optimal ignition timing.
Technical specifications
Intake air temperature sensor (1AT)/coolant temperature sensor (ECT).
| Temperature, C° | Resistance, Ohm | |
| EST | IAT | |
| 100 | 177 | 187 |
| 90 | 241 | 246 |
| 80 | 332 | 327 |
| 70 | 467 | 441 |
| 60 | 667 | 603 |
| 50 | 973 | 837 |
| 45 | 1188 | 991 |
| 40 | 1459 | 1180 |
| 35 | 1802 | 1412 |
| 30 | 2238 | 1700 |
| 25 | 2796 | 2055 |
| 20 | 3520 | 2500 |
| 15 | 4450 | 3055 |
| 10 | 5670 | 3760 |
| 5 | 7280 | 4651 |
| 0 | 9420 | 5800 |
| -5 | 12300 | 7273 |
| -10 | 16180 | 9200 |
| -15 | 21450 | 9200 |
| -20 | 28680 | 15080 |
| -30 | 52700 | 25600 |
| -40 | 100700 | 45300 |
Manifold Pressure (MAP) Sensor
| Pressure, kPa | Output voltage of the sensor, V |
| 100 | 4,9 |
| 90 | 4,4 |
| 80 | 3,8 |
| 70 | 3,3 |
| 60 | 2,7 |
| 50 | 2,2 |
| 40 | 1,7 |
| 30 | 1,1 |
| 20 | 0,6 |
| 10 | 0,3 |
| 0 | 0,3 |