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5.2.15. Sensors and executive mechanisms (Lucas EPIC)

ECU BLOCK

The ECU block – the main block of a control system of the engine. It operates system of injection of fuel and systems of decrease in toxicity of exhaust gases.

The ECU block receives signals from sensors which control the changing operational modes of the engine, such as temperature of the arriving air, temperature of cooling liquid, frequency of rotation of the crankshaft, the provision of a pedal of an accelerator, etc. These signals are used by the ECU block to define optimum amount of the fuel given by the fuel pump.

Removal

Before removal of any of elements of fuel system disconnect the negative plug of the accumulator.

PERFORMANCE ORDER
1. Uncover the ECU block.
2. Switch-off the electric socket, previously having lifted the lock lever in the top part of the socket.
3. Remove the socket from a back part, disconnect a forward part and remove the ECU block from pins.
4. Lift the ECU block up and remove it from a box.
5. Turn a connector of an electrical wiring of the fuel pump on the top part of a box clockwise.
6. Unhook a fastening ledge, using the screw-driver, then turn a connector counterclockwise and lift.
7. Unscrew two screws of fastening of the basis of a connector of an electrical wiring to a box of the block and lift the connector basis.
8. Unscrew internal and external bolts of fastening.
9. Remove a block box.

Installation

Installation is made in the sequence, the return to removal.

RPM METER AND PROVISIONS OF THE CRANKSHAFT

It is the inductive generator of impulses attached by bolts to a case of coupling and creating impulses when passing of crossing points about it between openings in a flywheel.

When passing each crossing point about the sensor one impulse by which the ECU block determines the frequency of rotation of the crankshaft is generated. One of crossing points between two openings is absent, and the ECU block determines position of the crankshaft by the admission of one signal.

Removal

PERFORMANCE ORDER
1. Track an electrical wiring from the sensor to a connector of an electrical wiring and disconnect it from the main plait.
2. Remove the rubber condensing ring, unscrew bolts and take the sensor from a case.

Installation

Installation is made in the sequence, the return to removal.

SENSOR OF TEMPERATURE OF COOLING LIQUID

The sensor of temperature of cooling liquid is a thermistor with negative temperature coefficient, that is at increase in temperature of the sensor its resistance decreases.

THE SENSOR OF TEMPERATURE OF THE ARRIVING AIR

The sensor of temperature of the arriving air is a thermistor with negative temperature coefficient, that is at increase in temperature of the sensor its resistance decreases. It is also used to correct amount of the given fuel.

Removal

PERFORMANCE ORDER
Switch-off the electric socket from the sensor and unscrew the sensor from system of inlet pipes in a forward part of the engine.

Installation

Installation is made in the sequence, the return to removal.

SENSOR OF PROVISION OF THE PEDAL OF THE ACCELERATOR

Information on the provision of a pedal of an accelerator is transferred to the ECU block by this sensor. The cable of an accelerator is connected to the sensor of provision of a pedal which transforms the movement of a pedal to an electric signal. After processing of this signal and using information obtained from other sensors, the ECU block operates the fuel pump of high pressure by means of electronics so that the optimum amount of fuel for obtaining desirable dynamics of the movement of the car moved.

Removal

PERFORMANCE ORDER
1. Remove an accelerator cable from the lever on the sensor of provision of a pedal of the accelerator located on the left forward side of a motor compartment.
2. Take an accelerator cable cover from the condensing ring in a sensor suspension bracket.
3. Switch-off the electric socket, unscrew bolts of fastening and remove the sensor with its suspension bracket. If it is necessary to remove the sensor from an installation suspension bracket, note position of the sensor concerning a suspension bracket, then unscrew two screws and remove the sensor.

Installation

Installation is made in the sequence, the return to removal.

THE SENSOR OF MEASUREMENT OF PRESSURE IN THE INLET COLLECTOR

The sensor of pressure measures vacuum in an inlet collector and transfers information to the ECU block for calculation of loading of the engine in any provision of a pedal of an accelerator.

The sensor can be installed in the lower part of the air filter or in other places in the forward left side of a motor compartment.

Removal

PERFORMANCE ORDER
1. Remove a vacuum hose and the electric socket and unscrew two bolts of fastening of the sensor.
2. Take the sensor from its nest.

Installation

Installation is made in the sequence, the return to removal.

SENSOR OF RAISING OF THE NEEDLE OF THE NOZZLE

The sensor of raising of a needle of a nozzle – an integral part of one of fuel nozzles which sends a signal to the ECU block when opening a nozzle.

CAR SPEED SENSOR

The sensor of speed of the car consists of the converter which is switched on in the speedometer drive. ECU uses sensor signals to change amount of the given fuel according to the speed of the movement of the car.

CONTROL UNIT OF SYSTEM OF PRELIMINARY HEATING

This relay operated by the ECU block, connecting to the ECU block of a glow plug of system of prestarting heating for a certain time at start of the cold engine.

EGR-VALVE

Return of a part of exhaust gases to an inlet collector is run by the ECU block in combination with the electromagnetic valve and the EGR valve. Vacuum from the vacuum pump goes to the EGR valve via the electromagnetic valve according to the frequency of rotation of the engine, loading and height.

Check

PERFORMANCE ORDER
1. If in system there is a malfunction, check that all electric sockets are connected and are not oxidized. Check that the filtering element of the air filter was pure, compression pressure in engine cylinders within norm and hoses of ventilation of the engine are not damaged.
2. If externally everything is all right, and malfunction is present at system, it is necessary to check fuel system for Peugeot stations.