2011 RENAULT SCENIC sensor

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-11V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
WITH FLOWMETER (K9K 728)
The flow of fresh air entering the engine is given by a hot wire ratiometric sensor. This flow sensor is used to
manage the amount of exhaust gas to be recirculated to ensure optimum recirculation rates. A fresh air temperature
sensor is built into the flowmeter.
Air flow measurement allows closed-loop control via the EGR valve.
Besides electrical faults with the sensor, there is a consistency test between the measured air flow and an estimated
air flow without EGR.
This flow evaluates the amount of fresh inlet air, based on the values supplied by the surrounding systems:
– the inlet air temperature measured by a sensor located after the turbocharger and/or after the intercooler (if fitted),
– the turbocharging pressure,
– the engine speed.
Pre-postheating actuation
Pre-postheating actuation consists of controlling the heater plugs and preheating warning light on the instrument
panel. The heater plugs are activated by relays, and the power is supplied from the battery. After the ignition is
switched on. Preheating is activated for a period of time. The warning light is illuminated for an activation period that
depends on the battery voltage, the atmospheric pressure, and the coolant temperature. When the temperature is
below a certain threshold, a postheating function can be used to improve the combustion stability, and consequently
engine operation (reducing unburnt particles and pollutant emissions).
Turbocharger control solenoid valve actuation
The turbocharger system comprises a solenoid valve that is used to actuate the vanes (or wastegate) to create an
overpressure or a vacuum in the inlet circuit.

13B-14V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
Temperature / emergency stop warning light
This indicator light is used both as an in-operation indicator light and as a system fault warning light. It illuminates for
3 seconds when the power is switched on (automatic test procedure controlled by the instrument panel)
Continuously lit: indicates engine overheating or a Level 2 fault.
– if the fault reaches a critical level, the injection cuts off automatically after several seconds.
– in the event of engine overheating, it is the driver's choice to stop the car or continue driving.
ACTIVATION PROGRAMMING OF THE INSTRUMENT PANEL WARNING LIGHTS
Orange SERVICE warning light (level 1)
This warning light comes on, accompanied by the faulty injection message.
The driver should have the repairs carried out as soon as possible.
Red STOP warning light (level 2)
This warning light comes on, accompanied by the faulty injection message.
The driver should have the repairs carried out as soon as possible.
Excess pollution OBD ORANGE warning light:
This warning light is used to alert the driver of any injection faults that could lead to excessive pollution, or if
the EOBD system has been deactivated. The injection computer requests illumination of the OBD warning light for
a present fault only after three consecutive driving cycles.
The 3 second visual inspection when the ignition is switched on (automatic test procedure managed by
the instrument panel) is carried out by the injection computer.
Faults that activate the OBD warning light
Associated
faultTitle Specification
DF010 EGR position sensor circuit CC.1 - CO.0
DF016 EGR control circuit CC.1
DF026 Cylinder 1 injector control circuit CO – CC
DF027 Cylinder 2 injector control circuit CO – CC
DF028 Cylinder 3 injector control circuit CO – CC
DF029 Cylinder 4 injector control circuit CO – CC
DF038 Computer 3. DEF
DF114 EGR solenoid valve circuit 4. DEF

13B-16V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
48-TRACK BROWN CONNECTOR B
Description Tracks Tracks Description
Flowmeter supply (728, 729) A1 G1 Knock sensor earth (pinking)
Flowmeter signal (728, 729) A2 G2 Fuel temperature signal
Flowmeter earth (728, 729) A3 G3 Fuel temperature sensor earth
Cylinder 1 injector + control A4 G4 Cylinder 4 injector + control
EGR feedback potentiometer supply B1 H1 Not used
EGR feedback potentiometer signal B2 H2 Coolant temperature signal
EGR feedback potentiometer earth B3 H3 Coolant temperature sensor earth
Cylinder 1 injector - control B4 H4 Cylinder 4 injector - control
Turbocharging pressure sensor supply C1 J1 Not used
Turbocharging pressure sensor signal C2 J2 Inlet air temperature signal
Turbocharging pressure sensor earth C3 J3 Inlet air temperature earth (722)
Cylinder 2 injector + control C4 J4 Not used
Rail pressure sensor supply D1 K1 Accelerometer shielding (pinking)
Rail pressure sensor signal D2 K2 External air temperature signal
Rail pressure sensor earth D3 K3 External air temperature earth
Cylinder 2 injector - control D4 K4 Not used
Not used E1 L1 Not used
Phase sensor signal (cylinder) E2 L2 Not used
Phase sensor earth (cylinder) E3 L3 EGR valve control
Cylinder 3 injector + control E4 L4 Not used
Knock sensor signal (pinking) F1 M1 Not used
Engine speed (TDC) sensor + signal F2 M2Turbocharging solenoid valve control
(728, 729)
Engine speed sensor earth (TDC) F3 M3 Not used
Cylinder 3 injector - control F4 M4 Fuel flow actuator control

13B-17V4 MR-372-J84-13B000$020.mif
DIESEL INJECTION
Fault finding – System operation13B
DDCR INJECTION
Vdiag No.: 44, 48
32-TRACK GREY CONNECTOR C
Description Tracks Tracks Description
Not used A1 E1 Not used
Water in diesel fuel detector earth A2 E2 Not used
Not used A3 E3 Not used
Not used A4 E4 Not used
Not used B1 F1 Supply relay control
Not used B2 F2 Preheating relay control
Water in diesel fuel detector signal B3 F3 Not used
Not used B4 F4 Not used
Not used C1 G1 Not used
Not used C2 G2 After relay + battery 1 earth
Refrigerant pressure sensor signal C3 G3 Refrigerant pressure sensor earth
Refrigerant pressure sensor supply C4 G4 Not used
Not used D1 H1 Potentiometer earth Gang 1
Not used D2 H2 Not used
Heater plug diag signal D3 H3 After relay + battery 2
Not used D4 H4 Not used
NOTE:
The supply voltage on tracks G2 and H2 is not measurable when the computer connector is disconnected.

13B-22V4 MR-372-J84-13B000$050.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
Tool faultAssociated
DTCDiagnostic tool title
DF001 0115 Coolant temperature sensor circuit
DF002 0070 Air temperature sensor circuit (728, 729)
DF003 2226 Atmospheric pressure sensor circuit
DF005 0335 Engine speed sensor circuit.
DF007 0190 Rail pressure sensor circuit
DF008 0225 Pedal potentiometer circuit track 1
DF009 2120 Pedal potentiometer circuit track 2
DF010 0409 EGR position sensor circuit
DF014 0500 Vehicle speed information circuit
DF015 0685 Main relay control circuit
DF016 0403 EGR control circuit
DF017 0382 Preheating unit control circuit
DF024 0231 Low pressure actuator control circuit
DF025 0380 Preheater unit diagnostic connection
DF026 0201 Cylinder 1 injector control circuit
DF027 0202 Cylinder 2 injector control circuit
DF028 0203 Cylinder 3 injector control circuit
DF029 0204 Cylinder 4 injector control circuit
DF037 0513 Engine immobiliser
DF038 0606 Computer
DF039 0110 Inlet air temperature sensor circuit
DF047 0560 Computer feed voltage
DIESEL INJECTION
Fault finding – Fault summary table