2011 RENAULT SCENIC mount

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-157V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 8
CONTINUED 2
If the engine does not start, only the static leak can be measured, that is the leak with the injector closed, not being
actuated and under high pressure.
Make sure that the ignition circuit is working correctly (minimum engine speed 200 rpm).
Tooling required
– Mot. 1711 Injector flow measuring kit.
Or: Use four tubes of internal diameter 4 mm and approximately 50 cm long and a test adapter (TEST IMV).
Procedure
– Switch off the ignition,
– disconnect the return pipes from the four injectors,
– cap the pump venturi tube to prevent the low-pressure circuit from depriming,
– connect the four transparent pipes in place of the return pipes (Mot. 1711),
– disconnect the low pressure actuator from the pump (brown IMV connector) and connect a test IMV or the
adapter of Mot. 1711,
– electrically disconnect the four injectors,
– switch on the ignition and engage the starter for 5 seconds,
– measure the amount of diesel fuel in each pipe.
Replace the injectors that have a leak return greater than 10 cm.
Switch off the ignition, and reconnect the four injectors electrically.
Disconnect the test IMV and reconnect the low-pressure actuator connector to the pump. Disconnect the
four transparent tubes and reconnect the injectors return circuit. Switch on the ignition again, and clear the injection
faults using the diagnostic tool.
A
NO

13B-160V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 11 Turbocharger air chain
Check for the air filter
Check the replacement interval of the air filter on the maintenance booklet.
Compare the part numbers of the air filter fitted to the vehicle and that of the air filter recommended by the
manufacturer.
Check the air filter direction of fitting.
Is the air filter fitted to the vehicle correct?
Check the condition of the air filter
Visually inspect the condition of the filtering section of the air
filter.
Is either the air filter or its seal damaged?
Is the air filter fouled (does it contain a lot of impurities)?Replace the air filter (see MR 364
(Mégane II) or 370 (Scénic II),
Mechanical, 12A, Fuel mixture, Air
filter, Removal - Refitting).
Low pressure circuit check
Note:
Depending on the vehicle type, the best visual access will be
either from above or from below.
Visually inspect the condition of the following components:
– fresh air inlet scoop on the front panel of the vehicle,
– air inlet pipe to the air filter,
– air pipe of the filter until the compressor inlet,
– mountings of the air flowmeter.
Is one of these components incorrect (disconnected,
cut, bent, pierced or kinked pipes)?Replace the defective parts (see MR
364 (Mégane II) or 370 (Scénic II),
Mechanical, 12B, Turbocharging).
YESNO
YES
NO
YES
A
NO
DDCR_V44_TEST11/DDCR_V48_TEST11