2011 RENAULT SCENIC fuel filter

13B-6V4 MR-372-J84-13B000$010.mif
DIESEL INJECTION
Fault finding – Introduction13B
DDCR INJECTION
Vdiag No.: 44, 48
You will always be asked for this log:
• when requesting technical assistance from the Techline,
• when requesting approval before replacing parts for which approval is compulsory,
• to be attached to monitored parts for which reimbursement is requested. The log is needed for warranty
reimbursement, and enables better analysis of the parts removed.
6. SAFETY INSTRUCTIONS
Safety rules must be observed during any work on a component to prevent any material damage or personal injury:
– check the battery voltage to avoid incorrect operation of computer functions,
– use the proper tools.
7. CLEANLINESS INSTRUCTIONS WHICH MUST BE FOLLOWED WHEN WORKING ON THE HIGH-
PRESSURE DIRECT INJECTION SYSTEM
Risks relating to contamination:
The high pressure direct injection system is highly sensitive to contamination. The risks associated with
contamination are:
– damage to or destruction of the high pressure injection system,
– components jamming,
– a component leaking.
All After-Sales operations must be performed under very clean conditions. This means that no impurities
(particles a few microns in size) should penetrate the system during dismantling.
The cleanliness principle must be applied from the filter to the injectors.
What are the sources of contamination?
– metal or plastic swarf,
– paint,
– fibres from cardboard, brushes, paper, clothing and cloth.
– foreign bodies such as hair,
– ambient air,
–etc.WARNING
BEFORE CARRYING OUT ANY WORK ON THE INJECTION SYSTEM, CHECK WITH THE DIAGNOSTIC
TOOL:
– that the rail is depressurised,
– that the fuel temperature is not too high.
IMPORTANT
Cleaning the engine using a high pressure washer is prohibited because of the risk of damaging connections. In
addition, moisture may collect in the connectors and create electrical connection faults.

13B-8V4 MR-372-J84-13B000$020.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
System outline
The DDCR injection system used on the K9 engine is an electronically managed high pressure injection system.
The fuel is compressed by a high pressure pump then stored in a rail that feeds the injectors. Injection occurs when
a current pulse is applied to the injector holders. The injected flow is proportional to the rail pressure and to
the applied pulse length, and the start of injection is phased with the start of the pulse.
The circuit comprises two subsystems, which are distinguished by the fuel pressure level.
– The low pressure system includes the tank, diesel fuel filter, transfer pump and injector holder return pipes.
– The high pressure circuit contains the high pressure pump, the rail, the injector holders and the high pressure tubes.
Finally, there are a certain number of sensors and regulating actuators for controlling and monitoring the entire
system.
Functions provided
Function: Fuel supply management (timing, flow and pressure).
Quantity of fuel injected and injection timing adjustment
The injection checking parameters are the quantities to be injected and their respective timing. These are calculated
by the computer using signals from the following sensors:
• Engine speed (Crankshaft + Cam for synchronisation)
• Accelerator pedal
• Turbocharging pressure and air temperature (Turbocharger pressure)
• Coolant temperature
• Air temperature
• Air load (Flow and Pressure)
• Rail pressure
• Flowmeter
• Turbocharging solenoid valve
The quantities to be injected and their respective timing are converted into:
• a reference tooth
• the time between this tooth and the start of the pulse
• the time for which the supply to the injector holder is on
An electrical current (pulse) is sent to each injector holder according to previously calculated data. The system
makes one or two injections (1 pilot injection, 1 main injection). The general principle is to calculate an overall
injected flow which will then be divided into a main injection flow and a pilot injection flow, to help the combustion
process work properly and to reduce pollutant emissions.
An accelerometer is used to monitor some of the fuel injection deviation. This has several roles:
• Protecting the engine by detecting injection leaks (disabled on the basic vehicle).
• Checking the pilot quantity by measuring deviation and dispersion
• By changing both the duration and timing of the injection, the quantity of fuel injected and the mixture ignition timing
can be adjusted.
DIESEL INJECTION
Fault finding – System operation

13B-9V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
Rail pressure check
The quality of combustion is influenced by the size of the atomised droplets in the cylinder. In the combustion
chamber, smaller fuel droplets will have time to burn fully, and will not produce smoke or unburned particles. To
meet the pollution requirements, the droplet size, and therefore the size of the injection holes, must be reduced.
With smaller holes, less fuel will be able to be introduced at a given pressure, which limits the power. To handle this
drawback, the injected fuel flow has to be increased, which means a pressure increase (and more apertures on the
injector nozzles). For the DDCR injection system, the pressure reaches 1400 bar in the rail, and must be constantly
regulated. The measuring circuit consists of an active pressure sensor on the rail connected to an analogue port on
the computer.
The High Pressure pump is supplied at low pressure (5bar) by a built-in transfer pump. This pump supplies the rail.
The rail filling pressure is controlled by the filling valve (IMV) and the discharge pressure is controlled by the injector
valves. This compensates for pressure drops. The filling actuator enables the high pressure pump to supply just
the exact quantity of diesel fuel required to maintain the rail pressure. This mechanism minimises the heat
generated and improves engine output.
In order to discharge the rail using the injector valves, the valves are actuated by short electrical pulses which are:
– short enough not to open the injector (and pass through the return circuit from the injectors),
– long enough to open the valves and discharge the rail.
The fuel surplus is sent back to the fuel filter or the tank, according to its flow. If there is no IMV control, the rail
pressure is limited by a discharge valve fitted on the pump.
Idling speed regulation
The computer handles the calculation of idling speed. This has to take account of the instantaneous power level to
be supplied, according to the following factors:
– Engine coolant temperature
– Gear engaged
– Battery charging
– Electrical consumers (Heating elements, Air conditioning, Fan assembly, Heated windscreen, etc.) active or
inactive
Individual injector correction (C2I)
The DDCR system injectors must be calibrated with corrective values to adjust their flow precisely. Each injector is
calibrated for different pressures on a test bench, and its specifications are shown on a label attached to the body of
the injector holders. These individual correction values are then written to the computer EEPROM, which can then
actuate the injectors by taking into account their manufacturing dispersion.

13B-10V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
Measuring the angular position (Cylinder reference sensor)
The angular position is measured using a magneto-inductive sensor triggered by machined teeth on the engine
flywheel. This flywheel has 60 teeth separated by six degrees, minus 2 missing teeth that form a notch.
A second sensor (Hall effect), activated by a machined tooth on the high pressure pump drive pulley
(synchronised with the camshaft), which rotates at half the engine speed, supplies a signal showing the progress of
the injection cycle. By comparing the signals from these two sensors, the computer's APS module (Angular Position
Subsystem) can supply the entire system with the synchronisation factors, namely: the angular position of
the flywheel, the engine speed, the number of the active injector, and the injection cycle timing. This module also
supplies the system with the engine speed signal.
Flow capacity function (VLC)
Because of the combination of several parameters such as the diesel fuel temperature, part wear, clogging of the
diesel filter, etc., the system may reach its limit during its service life. If this happens, the rail pressure cannot be
maintained because the pump lacks the necessary capacity. If the pump lacks the necessary capacity, this
programming will therefore reduce the requested flow to a value that will enable the pressure monitoring system to
control the pressure again.
The customer may have noticed a loss of vehicle performance when this program is activated (confirmed by
ET563 Flow capacity function). This is part of normal operation.
Function: Air flow management.
EGR valve control
The EGR (Exhaust gas recirculation) system comprises a proportional EGR valve with a built-in valve position
feedback potentiometer. The EGR valve position is controlled by the potentiometer in a closed loop and/or by
changes in the estimated air flow.
Calculation of the air flow
WITHOUT FLOWMETER (K9K 722)
Certain models are not fitted with air flowmeters. In this case the amount of fresh inlet air must be evaluated, based
on the values supplied by the surrounding systems. The (theoretical) air volume is calculated using a model with
these calculation parameters:
– the inlet air temperature measured by a sensor located after the turbocharger and/or after the intercooler (if fitted),
– the turbocharging pressure,
– the atmospheric pressure (external air),
– the EGR valve position,
– the fuel flow,
– the engine speed.
The atmospheric pressure sensor is optional. If fitted, it sends back an atmospheric pressure signal to an analogue
port on the micro-controller. If not, atmospheric pressure is recovered based on the turbocharger pressure
and the engine field.

13B-63
AFTER REPAIRDeal with any faults declared by the diagnostic tool. Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
V4 MR-372-J84-13B000$062.mif
DIESEL INJECTION
Fault finding – Interpretation of faults13B
DDCR INJECTION
Vdiag No.: 44, 48
DF057
STOREDWATER IN DIESEL FUEL DETECTOR CIRCUITCO.1: Open circuit or short circuit to +12 volts
CC.0: Short circuit to earth
1.DEF: Above maximum threshold (water present)
NOTESConditions for applying fault finding procedures to stored faults:
The fault is present with the engine running.
The level 1 warning light illuminates along with the message Check diesel filter.
CO.1
CC.0
NOTESNone.
Check for water in the diesel filter. Clean and replace the filter if necessary.
Check the condition and connection of the 3-track connector of the water detector.
Repair if necessary.
Check the connection and condition of the grey 32-track connector C of the computer.
Repair if necessary.
Check the insulation, continuity and the absence of interference resistance on the following connections:
Sensor connector track 3 Earth
Sensor connector track 2 Track B3 computer connector C
Sensor connector track 1 Track A3 computer connector B
Repair if necessary.
1.DEF
NOTESNone.
Bleed the diesel filter.
Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
DDCR_V44_DF057M/DDCR_V48_DF057M

13B-147V4 MR-372-J84-13B000$120.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
*Technical Note 3419: Fault finding on the turbocharger for petrol and diesel engines
NOTESOnly consult these tests when dealing with a fault finding chart (ALP) or when
interpreting faults.
Low pressure circuit check TEST 1
Electrical circuit checkTEST 2
Injector checkTEST 3
Inlet circuit checkTEST 5
High pressure system check TEST 6
High pressure circuit sealing check TEST 7
Injector return flowTEST 8
Diesel filter checkTEST 9
Turbocharger solenoid valve checkTEST 10: Apply
TEST 4 of
Technical Note
3419*
Turbocharger air chainTEST 11
TurbochargerTEST 12: Apply
TEST 7 of
Technical Note
3419*
Diesel fuel conformity check TEST 13
DIESEL INJECTION
Fault finding – Tests

13B-148V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 1 Low pressure circuit check
Check the conformity of the low pressure circuit
connections
Are the low pressure circuit connections correct? Carry out the necessary repairs.
Check the condition of the priming bulb, and that it is
working properly.
Look for leaks at the unions.
Are there leaks from the hoses and unions? Carry out the necessary repairs
Check that there are no air bubbles in the diesel fuel. Bleed the low-pressure circuit.
Place a container under the filter.
Disconnect the return hose from the filter and
plug the filter.
Pump using the priming bulb until there is no air
left.
Reconnect the return hose immediately. Are air bubbles present in the low pressure circuit?
Low pressure circuit correct.
NO
YES
YES
NO
YES
NO
DDCR_V44_TEST01/DDCR_V48_TEST01

13B-150V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 3 Injector check
Is diesel fuel present around the injectors?Locate the source of the leak and carry out the
necessary repairs.
Control the injectors with the commands
AC005 Cylinder 1 injector,
AC006 Cylinder 2 injector,
AC007 Cylinder 3 injector,
AC008 Cylinder 4 injector.Check the insulation and the continuity of the
electrical circuit.
Run test 9 Diesel filter check.
If test 9 is correct, replace the faulty injectors (MR 364
(Mégane II) or MR 370 (Scénic II), Mechanical, 13B,
Diesel injection, Diesel injector: Removal -
Refitting). Can you hear the valve moving when you are
1metre away from the vehicle?
End of TEST 3.YES
NO
NO
YES
DDCR_V44_TEST03/DDCR_V48_TEST03