10.8.1. Features of a design

The engine installed on the Ford Fusion cars is equipped with an electronic control system of the engine with the distributed fuel injection. This system provides performance of modern norms on toxicity of emissions and to evaporations of harmful substances at preservation of high road performance and low fuel consumption.
The actuation device in system is the electronic control unit (ECU). On the basis of information obtained from sensors, EBU counts parameters of regulation of injection of fuel and management of an ignition advancing corner. Besides, according to the put algorithm of EBU operates operation of the electric motor of the fan of the cooling system of the engine and electromagnetic coupling of turning on of the compressor of the conditioner, performs function of self-diagnostics of elements of system and notifies the driver on the arisen malfunctions.
At failure of separate sensors and EBU executive mechanisms includes the emergency operation providing operability of the engine.
The amount of the fuel given by nozzles is defined by duration of an electric signal from EBU. The electronic block traces data on a condition of the engine, counts the need for fuel and determines the necessary duration of supply of fuel by nozzles (signal duration). For increase in amount of the given fuel duration of a signal increases, and for fuel supply reduction — decreases.
The control system of the engine along with an electronic control unit includes sensors, actuation mechanisms, sockets and safety locks.
The Electronic Control Unit (ECU) is connected by electric wires with all sensors of system. Obtaining from them information, the block carries out calculations according to the parameters and a control algorithm which are stored in memory of the programmable read-only memory (PROM) and operates actuation mechanisms of system. The version of the program which is written down in memory of PPZU is designated by number assigned to this modification of EBU.
The control unit finds malfunction, identifies and remembers its code even if the refusal is unstable and disappears (for example, because of bad contact). The alarm lamp of malfunction of a control system of the engine in a combination of devices dies away through 10 from later maintenance of the refused knot.
After repair the code of malfunction which is stored in memory of the control unit needs to be erased. For this purpose power off the block on 10 with (take out a safety lock of a power-supply circuit of an electronic control unit or disconnect a wire from the minus plug of the rechargeable battery).
The block feeds with a direct current of 5 and 12 V various sensors and switches of a control system. As the electric resistance of power-supply circuits high, the control lamp connected to system conclusions does not light up. On conclusions of EBU it is necessary to use the voltmeter to determination of supply voltage with an internal resistance not less than 10 megohms.
EBU is not suitable for repair, in case of refusal it needs to be replaced.
The diagnostic socket serves for a conclusion from memory of EBU of codes of the malfunctions revealed during the work of a control system of the engine.
The diagnostic socket is located in interior of the car on the left side of the dashboard under a steering column and is hidden behind the folding panel. It is possible to connect the scanner which reads out information from the consecutive line of data to the diagnostic socket.
The sensor of provision of a bent shaft of inductive type is intended for synchronization of work of an electronic control unit with VMT of pistons of the 1st and 4th cylinders and the angular provision of a bent shaft.
The sensor is installed in a back part of the engine opposite to the setting teeths on a flywheel. The setting teeths are executed on a flywheel surface through equal intervals. One tooth is absent for creation of an impulse of synchronization (a "basic" impulse) which is necessary for coordination of operation of the control unit with VMT of pistons in the 1st and 4th cylinders.
At rotation of a bent shaft teeths change magnetic field of the sensor, directing impulses of tension of alternating current. The control unit determines the frequency of rotation of a bent shaft by signals of the sensor and gives impulses on nozzles.
At failure of the sensor launch of the engine is impossible.
The sensor of position of the camshaft (the phase sensor) of inductive type defines VMT of a step of compression of the piston of the 1st cylinder. The signal from the sensor is used by an electronic control unit and serves for the organization of the phased injection of fuel according to an operating procedure of cylinders. At emergence of malfunction in a chain of any of sensors the controller brings its code in the memory and includes an alarm lamp.
The sensor of temperature of cooling liquid is installed in the case of the distributor of cooling liquid from the back party of the engine. A sensitive element of the sensor is the thermistor which electric resistance changes in inverse proportion to temperature. At a low temperature of cooling liquid (–40 °C) resistance of a thermistor makes about 100 kOhm, at temperature increase to +130 °C — decreases to 70 Ohms.
The electronic block feeds temperature sensor chain with constant basic tension. Sensor signal tension as much as possible on the cold engine also decreases in process of its warming up. The electronic block determines temperature of the engine by value of tension and considers it when calculating adjusting parameters of injection and ignition. At failure of the sensor or violations in a chain of its connection of EBU establishes a code of malfunction and remembers it.
Besides the aforesaid, the sensor indirectly serves and as the sensor of the index of temperature of cooling liquid in a combination of devices. According to information from this sensor the electronic control unit the engine changes indications of the index. For elimination of malfunction check reliability of contact connections in conducting to the sensor or replace the sensor.
The combined sensor of absolute pressure in an inlet collector and temperatures of the soaked-up air is executed in the form of the variable resistor sensitive to change of pressure. It fixes change of pressure in an inlet collector according to changes of loading and turns of the engine. Depending on information obtained from the sensor, the controller registers amount of injectable fuel and a corner of an advancing of ignition.
The sensor of provision of a butterfly valve is executed for a single whole with a cover of throttle knot.
The sensor represents a potentiometer on which one end moves "plus" supply voltages (5 V), and other end is connected to "weight".
From the third conclusion of a potentiometer (from the toddler) there is an output signal to an electronic control unit.
When the butterfly valve turns (from impact on a pedal of management), tension at the sensor exit changes. At the closed butterfly valve it is lower than 0,5 Century. When the gate opens, tension at the exit of the sensor grows, at completely open gate it has to be more than 4 Century.
Tracing the output tension of the sensor, the controller corrects supply of fuel depending on the angle of opening of a butterfly valve (i.e. at the request of the driver).
The sensor of provision of a butterfly valve does not demand adjustment as the control unit perceives idling (i.e. full closing of a butterfly valve) as a zero mark.
The car speed sensor in the transmission is absent, its function is performed by the sensors of frequency of rotation of forward wheels of anti-blocking system (ABS) installed in rotary fists of a forward suspension bracket. Sensors of frequency of rotation of forward wheels transmit a signal, only a few from the pulse rings established on naves of forward wheels to the ABS control unit and in addition to an electronic control unit the engine. The principle of operation of the sensor is based on Hall's effect. The sensor gives on an electronic control unit rectangular impulses of tension with a frequency proportional to the speed of rotation of driving wheels.
Sensors of concentration of oxygen (lambda probes) are screwed in carving openings of a katkollektor. Install two sensors of concentration of oxygen on the Ford Fusion cars:
– the operating sensor intended for management of composition of fuel-air mix (on an entrance to converter);
– the diagnostic sensor intended for assessment of overall performance of converter (at the exit).
In a metal flask of the sensor the galvanic cell washed by a stream of the fulfilled gases is located. Depending on the content of oxygen in the fulfilled gases as a result of combustion of fuel-air mix sensor signal tension changes.
Sensors differ in parameters and have different markings. If at least one of sensors of concentration of oxygen is faulty, toxicity of the fulfilled gases can sharply increase, and fuel consumption to increase.
For convenience of replacement sensors differ in color of blocks. A block of a plait of wires of the sensor on an entrance to converter (managing director) – green color, and at the exit from converter (диагностическй) – violet.
Information from each sensor comes to the control unit in the form of signals low (from 0,1 B) and high (to 0,9 B) level. At a signal of low level the control unit obtains information on the high content of oxygen. The signal of high level testifies to the low content of oxygen in the fulfilled gases.
Constantly tracing tension of a signal of sensors, the control unit corrects amount of the fuel injected by nozzles. At low level of a sensor signal on an entrance to converter (poor fuel-air mix) the quantity given fuels increases, at the high level of a signal (rich mix) – decreases. If the difference between levels of signals of sensors on an entrance and an exit of converter is less than values, admissible at this operating mode, the control unit identifies malfunction of a katkollektor.
The sensor of a detonation is attached to the top part of the block of cylinders in a zone between the 2nd and 3rd cylinders and catches abnormal vibrations (detonation blows) in the engine.
Sensitive element of the sensor of a detonation is the pyezokristallichesky plate. At a detonation at the exit of the sensor tension impulses which increase with increase of intensity of detonation blows are generated. The controller on a signal of the sensor regulates an ignition advancing for elimination of detonation flashes of fuel.

1. Before removing any knots of a control system of fuel injection, disconnect a wire from the minus plug of the rechargeable battery.
2. Do not launch the engine if tips of wires on the rechargeable battery are badly tightened.
3. Never disconnect the rechargeable battery from onboard network of the car at the working engine.
4. At charging of the rechargeable battery disconnect it from onboard network of the car.
5. Do not subject EBU to temperature above 65 °C in working order and above 80 °C in non-working (for example, in the drying camera). It is necessary to remove EBU from the car if this temperature is exceeded.
6. Do not disconnect from EBU and do not attach to it a wire at the included ignition.
7. Before carrying out electrowelding works on the car disconnect wires from the rechargeable battery and a block of a plait of wires from EBU.
8. Carry out all voltage measurements the digital voltmeter with an internal resistance not less than 10 megohms.
9. The electronic knots applied in system of injection of fuel are calculated on very small tension therefore can be easily damaged by the electrostatic category. Not to allow damage of EBU, do not touch with hands its conclusions.
10. Diagnostics of a control system of the engine in all cases requires the special scanner therefore at emergence of malfunctions of system address on specialized service.