Contents: Petrol models ↡ Diesel models ↡
Petrol models
All petrol models must use unleaded petrol in their fuel systems. The engine management system is designed to provide maximum engine performance with minimum fuel consumption and emissions. The fuel vapor recovery system prevents fuel from escaping from the fuel tank into the atmosphere. An exhaust gas recirculation system is installed.
Functional diagrams of exhaust gas toxicity reduction systems (as parts of the engine management system)
Functional diagram of the injection system of engines 119 and 104 (engine 119 shown)
40 - Diaphragm pressure regulator; 55 - Fuel filter; 60 - Vacuum device; 74 - Fuel cooler; 75 - Fuel tank; 76 - Ventilation valve; 77 - Carbon adsorber of gasoline vapors; 89 - EGR valve (left on engine 120); 89a - Right EGR valve on engine 120; 98 - Pneumatic damper device for switching to overdrive; 125 - Air pump; 126 - Exhaust manifold air mixing cut-off valve; 127 - Check valve for mixing air into the exhaust manifold (left on engine 120); 127a - Check valve for mixing air into the right, on engine 120, exhaust manifold; 128 - Check valve (underpressure); 135 - Check valve (creating a vacuum); 136 - Vacuum chamber; 156 - Exhaust manifold; 158 - Catalytic converter; A1e26 - Malfunction Indicator Lamp (MIL/ "Check Engine"); A9 - Compressor K/V; A16 - Knock Sensors (KS); A16g1 - Left knock sensor KS; A16g2 - Right knock sensor KS; B2/2, B2/3 - Thermometric air mass sensor (MAF); B11/2 - 4-pin coolant temperature sensor (ECT); B11/7 - Intake air temperature sensor (IAT); B11/9 - Left ECT sensor; B17/5 - Left IAT sensor on engine 120; B17/6 - Right IAT sensor on engine 120; B17/7 - Intake air temperature sensor (IAT); G3/2 - Heated lambda probe (left on engine 120); G3/4 - Right heated lambda probe on engine 120; K17 - Relay for air mixing system in the exhaust manifold; K27 - Fuel pump relay; K27/1 - Left relay for fuel pumps 1 and 2 on engine 120; K27/2 - Right relay for fuel pumps 1 and 2 on engine 120; L5 - Crankshaft Position Sensor (CKP); L5/1 - Camshaft Position Sensor (CMP); L5/2 - Left CMP sensor on engine 120; L5/3 - Right CMP sensor on engine 120; L5/4 - Left CKP sensor on engine 120; L5/5 - Right CKP sensor on engine 120; M3m1 - Fuel pump 1; M3m² - Fuel pump 2; M16/1 - Acceleration actuator (throttle actuator); M16/3 - Left throttle actuator on engine 120; M16/4 - Right throttle actuator on engine 120; N1/3 - Ignition system control unit EZL/AKR; N1/4 - Left ignition system control unit on engine 120; N1/5 - Right ignition control unit on engine 120; N3/1 - ECM; N3/2 - Left ECM on engine 120; N3/3 - Right ECM on engine 120; N4/1 - Acceleration control unit (throttle actuator); N4/3 - Idle Speed Control (IAC)/Cruise Control Unit; N16/1 - Voltage stabilizer; N59 - Diagnostic module (californian models)
Functional diagram of the injection system of the 120 engine
R16/2 - Ignition module reference resistor; R16/3 - Reference resistor of the left ignition module on the 120 engine; R16/4 - Reference resistor of the right ignition module on the 120 engine; S29/3 - Idle speed limit switch; S40 - Cruise control switch; A - Off; B - Overclocking/installation; SP - Reinstallation; V - Engine braking/installation; S65 - Transmission Overload Safety Switch (band brake B1); S65/1 - Transmission overload safety switch (band brake B21). Engine 120; T1 - Ignition coil; T1/1 - Ignition coil of the right cylinder head on the 120 engine; T1/2 - Ignition coil of the left cylinder head on the 120 engine; Y3/3 - Pneumatic valve for upshift damper; Y27 - EGR changeover valve; Y27/2 - Left EGR switch on engine 120; Y27/3 - Right EGR switch on engine 120; Y32 - Exhaust manifold air mixing pump changeover valve; Y33 - Electromagnetic clutch for air mixing pump in exhaust manifold; Y49 - Camshaft Adjuster Solenoid Valve; Y49/1 - Left cylinder head camshaft adjuster solenoid valve on engine 120; Y49/2 - Solenoid valve for camshaft adjuster of right cylinder head on engine 120; Y58/1 - Carbon adsorber pneumatic switch; Y58/2 - Left pneumatic switch of the carbon adsorber on the 120 engine; Y58/3 - Right pneumatic switch of the carbon adsorber on the 120 engine; Y62 - Fuel Injectors (left bank of cylinders on engine 120); Y63 - Fuel injectors right bank of cylinders on engine 120
Vacuum line layout diagram (engines 104)
1 - Vacuum receiver; 2 - Vacuum distributor; 3 - Resonant damper; 4 - Air cut-off valve (with built-in check valve); 5 - Electric vacuum pump; 6 - Air pump switch valve; 7 - Vacuum control valve; 8 - Diaphragm pressure regulator; 9 - Manifold Absolute Pressure (MAP) Sensor; 10 - Purge control valve; 11 - To the carbon adsorber; 12 - Throttle actuator
Vacuum line layout diagram (engines 119)
1 - Vacuum receiver; 2 - Vacuum supply control valve; 3 - Diaphragm pressure regulator; 4 - Purge control valve; 5 - To the ME-SFI injection system control module; 6 - To the carbon adsorber; 7 - Electric air pump; 8 - Air supply shut-off valve; 9 - Manifold Absolute Pressure (MAP) Sensor; 10 - Air pump switch valve
Vacuum and evaporative line connections to the inlet manifold (engines 120)
40 - Diaphragm pressure regulator; 125 - Air pump; 126 - Air cut-off valve; 126a - Right air cut-off valve; 127 - Left check valve (air mixing); 128 - Vacuum control valve; 135 - Vacuum supply line check valve; 136 - Vacuum receiver; M16/3 - Left actuator of electronic accelerator/crankcase speed control/idle speed control device. On the left side of the power unit; M16/4 - Right electronic accelerator/crankcase speed control/idle speed control device actuator. On the right side of the power unit; Y32 - Air pump switch valve; Y33 - Air pump electromagnetic clutch; Y58/2 - Left purge control valve; Y58/3 - Right purge control valve; a - to the carbon adsorber; rt - red; gr - gray; sw - black; tr - neutral
The injector for the first cylinder is located in the right front part of the power unit (using a 12-cylinder engine as an example)
The fuel pump assembly is located under the vehicle, in front of the right rear axle shaft
The fuel pump relay is located on the right side of the luggage compartment, behind the rear fuse box
The fuel gauge is located in the left front corner of the luggage compartment, on the fuel tank
The intake manifold switching valve is located under the intake manifold (bottom view)
The left thermometric air mass meter (MAF) is located on the right side of the engine compartment, on the air intake sleeve
The left coolant temperature sensor is located on the left front of the power unit
The right coolant temperature sensor is located on the left side of the front of the power unit
The coolant temperature (ECT) sensor is located on the upper left front corner of the powertrain
The left knock sensor (KS) is located in a recess on top of the engine (in the picture the engine is removed from the car)
The left knock sensor (KS) 1 is located in a recess on top of the engine (in the picture the engine is removed from the car)
Right crankshaft position sensor (CKP) on V12 engine - rear on top of cylinder block (the engine is removed from the car)
Left Crankshaft Position (CKP) Sensor on V12 Engine - Right on rear wall of engine block (in the picture the engine is removed from the car)
Left pre-catalytic lambda probe 1 - under the car, close to the DP, above the catalytic converter
Pre-catalytic lambda probe 1 - under the car, close to the DP, on the tubular section of the exhaust system, in front of the catalytic converter
Left post-catalytic lambda probe 2, - under the car, near the DP
Post-catalytic lambda probe 2 - under the car, near the DP under the rear seat, in the exhaust pipe behind the catalytic converter
The electromagnetic clutch of the air mixing pump is located at the bottom in the right front corner of the engine compartment
The right purge valve of the adsorber is located on the left side of the engine compartment, on the mudguard of the wheel arch
The left purge valve of the adsorber is located on the right side of the engine compartment, on the mudguard of the wheel arch, behind the expansion tank of the cooling system
The purge valve of the adsorber is located in the left front corner of the engine compartment, on the mudguard of the wheel arch
The purge shut-off valve for the adsorber is located under the car, at the rear of the left rear wheel arch
Crankcase ventilation system (PCV)
To eliminate leaks of unburned hydrocarbons into the atmosphere, the engine is completely sealed. Gases and oil vapors formed in the crankcase enter the intake manifold through a mesh filter and burn in the cylinders together with the fuel.
Gases are removed from the crankcase due to the pressure difference in the crankcase and the intake manifold (crankcase pressure is higher).
Reducing toxicity of exhaust gases
To reduce harmful emissions into the atmosphere, all petrol models have a three-function catalytic converter built into the exhaust system. The fuel injection control system has a feedback loop that includes an oxygen sensor. This sensor, installed in the exhaust system, constantly informs the control unit about the composition of the exhaust gases. Depending on the data received, the control unit adjusts the quality of the mixture supplied to the combustion chambers and thus optimizes fuel combustion.
The lambda probe has a built-in heating element, which is switched on by the control unit via a special relay. The working surface of the lambda probe is sensitive to changes in the oxygen content in the gases. Depending on the oxygen concentration, the sensor sends signals of different voltages. If the mixture is over-enriched - the oxygen content in the exhaust gases is very low, the sensor sends signals with low voltage. The voltage increases as the mixture becomes leaner and the oxygen content in the gases increases. The converter works most effectively with an optimal composition of the combustible mixture (14.7 parts air to 1 part fuel). At the optimum concentration of oxygen in the exhaust gases, a jump in voltage occurs on the sensor. This jump is the starting point for the control unit when adjusting the mixture quality.
Two sensors are installed. One is before and the other is after the catalytic converter assembly. This allows for more accurate monitoring of the exhaust gas composition.
Exhaust Gas Recirculation (EGR) System
The exhaust gas recirculation system reduces the amount of NOx in the exhaust gases. To do this, a small portion of the exhaust gases is fed into the intake manifold through a special valve. The recirculation system valve is controlled by the control unit.
Fuel Evaporative Emissions (EVAP) System
Refer to the engine management system diagrams (Engine Management System for 3.2L Models, Engine management system for 4.2 and 5.0L models).
To reduce the emission of unburned hydrocarbons into the atmosphere, all petrol models are equipped with a fuel vapor recovery system. The fuel filler neck of the fuel tank is hermetically sealed with a lid, and a carbon adsorber is installed under the fuel tank. It collects fuel vapors that form in the tank when the car is parked and stores them there until the control unit signals the filter to begin purging. Then the fuel vapors begin to flow through the purge valve(s) into the intake manifold, where they mix with the working mixture and then burn in the usual way in the combustion chambers.
To ensure normal engine operation at idle speed and during warm-up, the control unit keeps the valve closed. This prevents unburned fuel from entering the converter (at high idle speed the mixture is too rich). After the engine warms up, the valve begins to open and close, supplying fuel vapors into the intake tract.
Diesel models
The engine management system operates in such a way as to obtain maximum output from the engine with minimum fuel consumption and toxicity of exhaust gases. To further reduce toxicity of gases, several additional systems are installed on the car. The crankcase ventilation system reduces gas leaks into the atmosphere from the engine lubrication system. The catalytic converter reduces toxicity of exhaust gases. An exhaust gas recirculation system is installed.
Continuous crankcase ventilation (PCV) system
To eliminate leaks of unburned hydrocarbons into the atmosphere, the engine is completely sealed. Gases and oil vapors formed in the crankcase enter the intake manifold through a mesh filter and burn in the cylinders together with the fuel.
Gases are removed from the crankcase due to the pressure difference in the crankcase and the intake manifold (crankcase pressure is higher). All diesel models are equipped with a ventilation valve. It is located on the cylinder head cover and controls the flow of gases from the crankcase.
Catalytic converter
To reduce the amount of harmful emissions into the atmosphere, all diesel models have a catalytic converter built into the exhaust system. It neutralizes most of the gaseous hydrocarbons, CO and other harmful impurities that are part of the exhaust gases.
Exhaust gas recirculation system
All diesel models are also equipped with an exhaust gas recirculation system. This system reduces the amount of NOx in the exhaust gases. To do this, a small portion of the exhaust gases is fed into the intake manifold through a special valve. The recirculation valve is controlled by the control unit.