2000 RENAULT SCENIC sensor

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Special notes
13
13-4
OPERATION
The common rail direct high pressure injection system is a sequential diesel injection system (based on the
operation of multipoint injection for petrol engines).
This new injection system reduces operating noise, lowers the quantity of polluting gas and particles and produces
significant engine torque at low engine speeds thanks to a pre-injection procedure.
The low pressure pump (also called the supercharging pump) supplies the HP pump, through the filter with pressure
of between 2.5 and 4 bars.
The HP pump generates the high pressure sent to the injection rail. The pressure regulator located on the pump
modulates the value of the high pressure via the computer. The rail supplies each injector through a steel pipe.
The computer:
– determines the value of injection pressure necessary for the engine to operate well and then controls the pressure
regulator. It checks that the pressure value is correct by analysing the value transmitted by the pressure sensor
located on the rail,
– determines the injection time necessary to deliver the right quantity of diesel and the moment when injection should
be started,
– controls each injector electrically and individually after determining these two values.
The injected flow to the engine is determined depending on:
– the duration of injector control,
– the injector opening and closing speed,
– the needle stroke (determined by the type of injector),
– the nominal injector hydraulic flow (determined by the type of injector),
– the high pressure rail pressure controlled by the computer.
FOR ANY INTERVENTION IN THE HIGH PRESSURE INJECTION SYSTEM YOU MUST RESPECT THE
CLEANING AND SAFETY ADVICE SPECIFIED IN THIS DOCUMENT.

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Special notes
13
13-5
POST-REPAIR CHECK
A fuel cock is fitted to the fuel filter at the level of the diesel return pipe leading to the tank. It should be in open
position for normal operation.
However, to carry out a circuit reignition after an intervention, a filter change or a fuel fault, you should:
– close the fuel cock,
– start the low pressure pump by switching on the ignition several times,
– start the engine,
– OPEN THE FUEL COCK (the valve is open when the two coloured lines are aligned).
NOTE: certain vehicles are not fitted with a fuel cock. In this case, ignore this operation.
IMPORTANT: the engine must not run with diesel containing more than 10 % diester.
The system can inject the diesel into the engine up to a pressure of 1350 bars. Before any intervention, check
that the injector rail is depressurised.
It is absolutely vital that you observe the tightening torque:
– of the high pressure pipes,
– of the injector on the cylinder head,
– of the pressure regulator,
– of the pressure sensor.
When the high pressure pump, injectors, supply, return and high pressure output unions are repaired or
removed, the bores should be fitted with new and appropriate core seals to avoid impurities.
When replacing a high pressure pipe, the following procedure should be observed:
– remove the high pressure pipe,
– fit the cleanliness plugs,
– loosen the high pressure rail and the pump/rail pipe,
– fit the high pressure pipe,
– tighten the injector side union to torque,
– tighten the connection on the high pressure pump side to torque,
– tighten the high pressure rail fastenings to torque.
– tighten the pump/rail pipe to torque (pump side first).
It is prohibited to remove the interior of the pump.
It is vital that you replace the fuel return pipe placed on the injectors during removal.
The diesel temperature sensor is not removable. It is part of the fuel return rail.
It is forbidden to loosen a high pressure pipe connection when the engine is running.After any operation, check that there are no diesel leaks. Start the engine at idling speed until the fan starts up,
then accelerate several times under no load.

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Location of components
13
13-9
Location of components
1
2
3
4
5
6
7
8
9
10
11
12
13
14Injection computer
Cylinder marking sensor
Solenoid injector
Rail pressure sensor
Flow meter with air temperature sensor
EGR valve
Turbocharger pressure sensor
Preheating unit
Turbocharging pressure regulator (solenoid)
Accelerator pedal potentiometer
Engine speed sensor and coolant temperature sensor
Fuel pressure regulator
Fuel temperature sensor (depending on version)
High pressure pump

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Location of components
13
13-10
16192R
1
2
3
4
5
6High pressure pump
Common injection rail
Injector
Pressure regulator
Pressure sensor
Water temperature sensor

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Location of components
13
13-11
16181R
7
8
9Cylinder marking sensor
Turbocharger
Priming catalytic converter
16155R2
11
12
13
14EGR solenoid valve
Turbo regulation solenoid
Turbocharger pressure sensor
Preheating unit
16869R3
15
16
17Injection computer
Fuel filter
Repriming fuel cock
16870R2

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Injection warning light
13
13-12
Injection warning light
Vehicles using the high pressure diesel system are fitted with two injection warning lights used during the preheating
phase and in case of an injection fault (or engine overheating).
WARNING LIGHT PRINCIPLE
!When ignition is switched on, the preheating light is lit during the preheating phase and then goes out (see section
13 "Pre-postheating control").
!When there is a fault on the injection system the "fault" warning light lights up. These faults are:
– internal computer fault,
– engine speed fault (the vehicle doesn't start),
– main relay or low pressure fault (the vehicle doesn't start),
– injector fault,
–TDC sensor coherence fault and camshaft sensor,
– rail pressure sensor fault,
– rail pressure regulator fault,
– accelerator potentiometer fault,
– engine immobiliser fault,
– computer supply voltage fault,
– engine overheating.
NOTE: the OBD warning light (symbolised by an engine), visible when the ignition is switched on, is never visible
when the engine is running.

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Injector rail
13
13-28
REMOVAL
Disconnect:
– the battery,
– the pressure sensor (1),
– the injectors,
– the cylinder marking sensor.
Undo and remove the diesel HP pipes.
Insert the plugs to maintain cleanness.
Gently remove the injection rail.YOU SHOULD FOLLOW THE CLEANNESS INSTRUCTIONS CLOSELY
16192-2R

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Pressure sensor
13
13-38
Pressure sensor
TIGHTENING TORQUES (In daN.m or/and°)
Pressure sensor 3.5 ± 0.5
IMPORTANT: before any intervention, connect
the after-sales diagnostic tool, query the injection
computer and check that the injection rail is not
under pressure. Take note of the fuel temperature.
PRESSURE SENSOR (1)
REMOVAL
Disconnect the battery.
Remove the sensor connector.
Unscrew the pressure sensor.REFITTING
Replace the seal.
Screw in the sensor then tighten it to torque.
Connect the connector. YOU SHOULD FOLLOW THE CLEANNESS
INSTRUCTIONS CLOSELY.
After any intervention, check that there are no leaks in the diesel circuit.
Start the engine at idling speed until the fan starts up, then accelerate
several times under no load.
16192R2