Sequential fuel injection (SF1).
• 4 nozzles.
Air intake system
Air flow meter (MAF sensor) with heated wire element.
Ignition system with electronic digital control
Integrated electronic ignition system with electronic digital control (the EDIS module is integrated into the EDIS control unit in the EEC-V-PCM).
Security switch
• The mechanical safety switch is installed on the side in front of the driver's door.
Exhaust gas composition adjustment
• Catalytic Converter (TWC), installed in the exhaust pipe.
Heated oxygen sensor (HO2S), installed in the exhaust manifold.
Exhaust gas recirculation system (EGR).
Fuel vapor recovery system (EVAP).
Diagnostic capabilities
Central diagnostic connector (DLC) located behind the side trim of the left A-pillar.
Processor Diagnostics (CPU) instrument FDS 2000.
The main elements of the EEC-V fuel injection system
EEC-V-PCM control unit.
Pic. 8.2. The main elements of the EEC-V fuel injection system: 1 - air flow meter (MAP); 2 - throttle position sensor (TP); 3 - temperature sensor of the air entering the engine (IAT); 4 - coolant temperature sensor (ECT); 5 – coupling of the conditioner compressor; 6 - crankshaft angle sensor (CKP); 7 - camshaft position sensor (CMP); 8 - oxygen sensor (HO2S); 9 – electronic pressure drop converter; 10 – the switch of the amplifier of a steering (PSP); 11 - speed sensor (VSS); 12 - relay; 13 - ignition switch with anti-theft device; 14 - battery; 15 - diagnostic connector (DLC); 16 - fuel pump relay (FPR); 17 - battery safety switch (IFS); 18 - fuel pump (FP); 19 - nozzle; 20 - solenoid valve of the EAVAP fuel vapor recovery system; 21 - idle speed control valve (IAC); 22 - EGR vacuum regulator (EVR); 23 – the switch of the fan of the air conditioning system; 24 - engine start blocking block (PATS)
The electronic control unit, based on information from sensors, provides constant monitoring of engine operating conditions (pic. 8.2). The analog to digital converter converts filtered input signals such as engine speed, intake manifold absolute pressure, coolant temperature, etc. into digital form, allowing all information to be processed in the microprocessor before being sent to the output circuits. The output amplifier circuits convert the low power signals into the power required by the various actuators in the system. Depending on the load and temperature, the control unit provides an output signal to inject a certain amount of fuel. In this case, the control unit varies the opening time of the electromagnetic fuel injectors. The memory of the control unit stores programs and setting data. The EEC-V-PCM control unit allows reprogramming to newer engine control programs using the FDS 2000.
Fuel injection battery safety switch.
Pic. 8.3. Location of the fuel injection battery safety switch
On all Fiesta vehicles (except vehicles with diesel engines) the switch is located on the side in front of the driver's door (pic. 8.3). The switch cuts off the fuel supply in the event of an accident or heavy impact.
Air flow meter (MAF sensor) -
installed in front of the throttle assembly, measures the mass of air entering the engine. After passing through the air filter, the air entering the engine passes through an air mass meter with a heated wire element forming part of the electrical bridge circuit. The current passing through this wire element maintains its temperature at a constant level, which is higher than the temperature of the intake air.
At idle, with the throttle closed, only a small amount of air flows past the heated wire, causing it to cool slightly. As the accelerator pedal is depressed and the throttle is opened more, more air flows past the wire element and the degree of its cooling increases.
Due to the decrease in temperature, the wire element changes the electrical resistance and the electric current flowing through it. This change in current informs the control unit about the amount of air entering the engine. In this way, changes in air pressure and temperature can be taken into account. The wire element air mass meter has no moving parts and its aerodynamic drag inside the intake tract is negligible.
MAF air flow meter signals affect the correction and operation of the following systems:
- the amount of fuel injected into the engine cylinders;
- ignition timing;
- idle speed control valve position (IAC);
- fuel vapor recovery (EVAP);
- exhaust gas recirculation (EGR);
- oxygen regulation.
Throttle position sensor (TP) -
installed directly in the throttle assembly, actuated by the throttle valve shaft and registers the position of the throttle valve at the moment.
Sensor signals affect the adjustment and operation of the following systems:
- the amount of fuel injected into the engine cylinders;
- frequency of rotation of the crankshaft of the engine at idle;
- ignition timing;
- exhaust gas recirculation (EGR).
Intake air temperature sensor -
mounted in a plastic air filter housing. The sensor signals are important for adjusting the following:
- the amount of fuel injected into the engine cylinders;
- idle speed of the engine crankshaft.
coolant temperature sensor (ECT) -
is a temperature sensitive element (thermistor), installed in the cylinder head, based on its signal, the control unit corrects the following:
- frequency of rotation of the crankshaft of the engine at idle;
- ignition timing;
- exhaust gas recirculation (EGR);
- fuel vapor recovery (EVAP).
Crank angle sensor (CKP) -
Pic. 8.4. Sensor location (1) angle of rotation of the crankshaft and the impulse sector on the flywheel (2)
installed on all Fiesta engines on the gearbox housing flange and registers the exact position and speed of the crankshaft (pic. 8.4). The sensor signals are important for the adjustment of the following systems:
- the amount of fuel injected into the engine cylinders;
- ignition timing;
- idle speed of the engine crankshaft;
- exhaust gas recirculation (EGR).
If the inductive crankshaft angle sensor fails (CKP) further operation of the engine is not possible until the sensor is replaced.
Camshaft position sensor (CMP) -
installed in the cylinder head in front of the first cam of the exhaust camshaft. The sensor operates on an inductive principle and controls the fuel injection sequence.
The sensor signal allows the EEC-V-PCM control unit to determine, based on the ignition sequence, which cylinder and in which sequence to supply fuel.
oxygen sensor (HO2S) -
installed in the exhaust manifold and transmits information about the residual oxygen content in the exhaust gases. To reduce the response time to 3 s, the sensor is heated after each start of a cold engine. The sensor signal influences the correction:
- the amount of fuel injected into the engine cylinders;
- fuel vapor recovery (EVAP).
The oxygen sensor is of great importance for the function and life of the catalytic converter.
Differential pressure transmitter electronic sensor (DPFE) -
mounted on a bracket on the front wall of the engine compartment together with the solenoid valve for the exhaust gas recirculation system and the solenoid valve for the fuel vapor recovery system (EVAP). Based on the DPFE sensor signal, the control unit corrects:
- the mass of exhaust gases sent for re-burning;
- position of the electronic vacuum regulator (EVR).
Power Steering Button Switch (PSP) -
installed on the right in the engine compartment in the pressure line of the hydraulic system of the power steering. In the neutral position, the switch is off and is activated only when the pressure in the hydraulic system increases. Based on the signal from the switch, the EEC-V-PCM control unit increases the idle speed. Based on the DPFE sensor signal, the control unit corrects:
- the position of the engine idle speed control valve;
- the amount of fuel injected into the engine cylinders;
- ignition timing.
Speed sensor (VSS) -
installed in the gearbox housing and transmits a signal to the control unit about the speed of the vehicle. Based on the VSS sensor signal, the control unit corrects:
- frequency of rotation of the crankshaft of the engine when the vehicle is coasting;
- turn off shift on mountain roads.
Drive Neutral Switch (NDS) -
installed in the crankcase of the CTX automatic transmission. NDS switch signals limit:
– the maximum frequency of rotation of the engine crankshaft in the neutral position of the gearbox at the level of 4000 min-1.
Actuators and devices of the EEC-V fuel injection system
The valve for adjusting the engine crankshaft speed at idle (IAC) - installed in the air intake pipe.
Vacuum EGR regulator (EVR) -
mounted on a bracket on the front wall of the engine compartment. The EGR solenoid valve responds to a clock signal from the EEC-V control unit and releases a control vacuum for the EGR valve.
Evaporative Emission Solenoid Valve (EVAP) -
mounted on a bracket on the front wall of the engine compartment. Implements temperature and load dependent signals of the EEC-V control unit. When the valve is opened, fuel vapor from the activated carbon tank enters the intake tract.
Nozzles -
Pic. 8.5. Fuel distribution pipeline (2) with nozzles (1)
installed in a common fuel distribution pipeline (pic. 8.5).
Exhaust gas recirculation system for Zetec-SE engines
Pic. 8.6. The relationship of the elements of the EGR exhaust gas recirculation system: 1 - EGR vacuum regulator (EVR); 2 – electronic differential pressure transducer (DPFE); 3 - fuel pressure regulator; 4 – pressure drop section; 5 - EGR valve
The EGR system of the Zetec-SE engines operates in a temperature dependent part load range. When starting the engine and during its warm-up, the temperature of the coolant is of decisive importance. The DPFE sensor determines the set exhaust pressure difference and from this determines the actual pressure drop. The voltage signal enters the EEC-V-PCM and then in a modified form is supplied to the EGR vacuum regulator (EVR). Ultimately, the EVR controls the EGR valve, which allows a well-defined mass of exhaust gases to enter the intake manifold behind the throttle (pic. 8.6).
Diagnostic elements in the EEC-V fuel injection system
Diagnostic connector (DLC) -
Pic. 8.7. Location of the diagnostic connector (1) at the bottom of the left front pillar
installed behind the upholstery at the bottom of the left A-pillar (pic. 8.7). Access to it opens after removing the protective cover.
Processor block (CPU).
Pic. 8.8. Appearance of the processor unit (CPU)
If the computer program EEC-V-PCM is not compatible with the diagnostic equipment, the CPU unit replaces it with one understandable by the FDS 2000 equipment.
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