2009 RENAULT SCENIC Engine And Peripherals EDC16 Workshop Manual

DIESEL INJECTION
Fault finding – System operation13B
13B - 9V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51DIESEL INJECTION
Fault finding – System operation
System outline
The high pressure injection system is designed to deliver a precise quantity of diesel fuel to the engine at a set
moment.
It is fitted with a 112-track BOSCH EDC16 C3 type computer.
The system is comprised of:
–a priming bulb on the low pressure circuit,
–a diesel filter,
–a high pressure pump with a built-in low pressure pump (transfer pump),
–a high pressure regulator mounted on the pump,
–an injector rail,
–a diesel fuel pressure sensor built into the rail,
–four solenoid injectors,
–a coolant temperature sensor,
–a cylinder reference sensor,
–an engine speed sensor,
–a turbocharger pressure sensor,
–an accelerator pedal potentiometer,
–an EGR solenoid valve,
–an atmospheric pressure sensor integrated into the injection computer,
–an air flow sensor with an air temperature sensor,
–a turbocharging pressure limitation solenoid valve,
–a motorised damper valve.
The common rail direct high pressure injection system works sequentially (based on the petrol engine multipoint
injection).
This injection system reduces operating noise, reduces the volume of pollutant gases and particles and produces
high engine torque at low engine speeds thanks to a pre-injection procedure.
The high pressure pump generates the high pressure and transmits it to the injector rail. The actuator located on the
pump controls the quantity of diesel fuel supplied, according to the requirement determined by the computer. The rail
supplies each injector through a steel pipe.
MR-372-J84-13B250$135.mif

DIESEL INJECTION
Fault finding – System operation13B
13B - 10V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
a) The computer:
Determines the value of injection pressure necessary for the engine to operate correctly and then controls the
pressure regulator.
Checks that the pressure value is correct by analysing the value transmitted by the pressure sensor located on the rail.
Determines the injection duration necessary for supplying the correct quantity of diesel and the moment when
injection is required; controls each injector electrically and individually after determining these values.
The flow injected into the engine is determined by:
–the duration of injector control,
–the rail pressure (regulated by the computer),
–the injector opening and closing speed,
–the needle stroke (determined by a constant for the type of injector),
–the nominal hydraulic flow of the injector (specific to each injector).
The computer manages:
–idling regulation,
–exhaust gas flow reinjection to the inlet (EGR),
–fuel supply check (advance, flow and rail pressure),
–the CMV control via the Protection and Switching Unit (centralised coolant temperature management function),
–the air conditioning (cold loop function),
–the cruise control/speed limiter function,
–pre-post heating control,
–fault warning lights via the multiplex network.
The high pressure pump is supplied at low pressure by an integrated low pressure pump (transfer pump).
It supplies the rail, the pressure of which is controlled by the fuel flow actuator (MPROP) for charging, and for
discharging by the injector valves. This compensates for pressure drops. The fuel flow actuator enables the high
pressure pump to supply the exact quantity of diesel fuel required to maintain the rail pressure. This component
minimises the heat generated and improves engine output. In order to discharge the rail using the injector valves, the
valves are controlled by brief electrical pulses which are:
–short enough not to open the injector (passing through the feedback circuit from the injectors),
–long enough to open the valves and discharge the rail.

DIESEL INJECTION
Fault finding – System operation13B
13B - 11V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
b) Multiplex connection between the different vehicle computers.
The electronic system fitted in this vehicle is multiplexed.
This enables dialogue between the various vehicle computers. As a result:
–the activation of the fault warning lights on the instrument panel is performed by the multiplex network, with the
vehicle speed sensor on the gearbox deactivated,
–vehicle faults are displayed by the multiplex network,
–the vehicle speed sensor on the gearbox is not needed.
The vehicle speed signal on the instrument panel is transmitted by the ABS computer via a wire connection, then
sent out on the multiplex network by the instrument panel. The vehicle speed signal is used mainly by the injection
computer and the airbag computer.
Some vehicles have adopted a sensor for detecting water in the diesel fuel, located in the filter. If there is water in the
diesel fuel, the orange "Injection and pre-post heating" warning light will come on.
The system can inject diesel fuel into the engine at a pressure of up to 1600 bar. Before each operation, check that
the injector rail is depressurised and that the fuel temperature is not too high.
You must respect the cleanliness guidelines and safety advice specified in this document for any work on the high
pressure injection system.
Removal of the internal parts of the pump and injectors is prohibited. Only the fuel flow actuator, the diesel fuel
temperature sensor and the venturi can be replaced.
For safety reasons, it is strictly prohibited to undo a high pressure pipe union when the engine is running.
It is not possible to remove the pressure sensor from the fuel rail because this may cause circuit contamination
faults. If the pressure sensor fails, the pressure sensor, the rail and the five high pressure pipes must be replaced.
It is forbidden to remove any injection pump pulley bearing the number 070 575. If the pump needs to be replaced,
replace the pulley.
Supplying + 12 V directly to any component in the system is prohibited.
Ultrasonic decoking and cleaning are prohibited.
Never start the engine unless the battery is connected correctly.
Disconnect the injection computer when carrying out any welding work on the vehicle.WARNING
The engine must not operate with:
–Diesel fuel containing more than 10 % diester,
–petrol, even in tiny quantities.

DIESEL INJECTION
Fault finding – System operation13B
13B - 12V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
c) Hosted functions:
Air conditioning management assistance:
In the case of vehicles with climate control, the EDC16 system has the option of deactivating the air conditioning via
the UCH, under certain conditions of use:
–when requested by the driver,
–when starting the engine,
–if the engine overheats (in order to reduce the power the engine has to supply),
–when the engine speed is kept at a very high level (to protect the compressor),
–during transitory phases (such as demands for high acceleration when overtaking, anti-stall and start-up) These
conditions are only taken into account when they do not occur repeatedly, to prevent instability in the system
(erratic deactivations),
–when certain faults appear.
Cold loop air conditioning management:
The air conditioning is the cold loop type and its management shared between several computers.
The injection computer is responsible for:
–authorising cold requests according to the refrigerant pressure, the engine coolant temperature and the engine
speed,
–calculating the power absorbed by the compressor (from the refrigerant pressure),
–requesting operation of the GMV, from the UPC, according to the vehicle speed, the refrigerant pressure and the
engine coolant temperature.
The driver requests the air conditioning to be switched on by means of the ventilation selector coupled to a switch.
The cold air request is authorised or denied depending on the pressure measured. If this pressure is outside the
operating limits, the cold loop program is not activated.
Management of the damper valve:
The damper valve currently has three functions:
–the valve closes in order to block the passage of air towards the cylinders to shut off the engine. The aim of this is
to stop the engine as quickly as possible and to reduce instabilities as the engine is switched off.
–"valving" function depending on the engine operation: the damper valve closes by a few % to create a ''venturi''
effect at the EGR valve passage section.
The aim of this is to accelerate the air flow of EGR gases and to reduce the emission of pollutants.

DIESEL INJECTION
Fault finding – System operation13B
13B - 13V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
Passenger Compartment Heating Resistor Management:
In order to reduce the time required to heat up the passenger compartment, the vehicle is fitted with Passenger
Compartment Heating resistors (RCH). These passenger compartment heating resistors are run and controlled by
the UCH. The injection computer authorises or prohibits the operation of the passenger compartment heating
resistors according to the operating phases and engine power needs.
Cruise control/speed limiter management:
The vehicle cruise control function, when activated, allows you to keep the vehicle speed at a selected value
regardless of the driving conditions encountered.
Using the control buttons, the driver can increase or reduce the speed of the vehicle.
If the driver wishes to exceed the cruising speed, he may:
–depress the accelerator pedal and exceed the cruising speed (the vehicle will return to the initial cruising speed
once the driver takes his foot off the pedal),
–press the system control buttons.
The cruise control function can be deselected either by:
–the system control buttons,
–deactivating the cruise control switch,
–when system events are detected, such as the brake pedal or clutch being depressed,
–when system errors are detected such as an inconsistent vehicle speed.
The cruise function can also be temporarily disabled when the driver wants to increase speed by depressing the
accelerator pedal. The cruising speed is resumed when the driver releases the accelerator pedal.
The vehicle will then attempt to reach the cruising speed at a controlled acceleration rate.
It is possible to reactivate the vehicle speed control and resume the last cruising speed after deactivation (computer
supply not cut off).
When activated (using the selection switch) the vehicle speed limiter function limits the vehicle speed to a
preselected value. The driver controls the vehicle in the normal way using the accelerator pedal until the limit speed
is reached.
If an attempt is made to exceed this speed, the system ignores the pedal request and controls the vehicle speed in
the same way as the cruise control function, provided that the driver keeps the accelerator pedal sufficiently
depressed.
Like the cruise control function, the limit speed can be modified by pressing or pressing and holding the control
buttons.
For safety reasons, it is possible to exceed the limit speed by depressing the accelerator pedal and exceeding the
pedal position limit value. The vehicle speed is then totally controlled as a function of pedal position until the speed
falls back below the limit speed when the speed limiter function will once again be reactivated.
If the driver wishes to exceed the cruising speed, he may:
–exceed the accelerator pedal's kickdown point,
–increase the limit speed by pressing or pressing and holding the limit speed switch.
The speed limiter function can be deselected either:
–the system control buttons,
–by switching off the speed limiter switch,
–when system events are detected, such as the brake pedal or clutch being depressed,
–when system errors are detected such as an inconsistent vehicle speed.

DIESEL INJECTION
Fault finding – System operation13B
13B - 14V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
Exhaust gas recirculation management
The exhaust gas recirculation system comprises a direct current EGR valve controlled by an H bridge in the
computer. This system has a built-in valve position feedback potentiometer.
The EGR valve is controlled in a closed loop on the change in the air flow measured by the flow sensor.
The potentiometer is used in the fault finding procedure for the EGR valve position.
Warning light management:
Instrument panel display
The computer manages the data display on the instrument panel relating to engine operation. This involves six
functions:
–the pre-postheating warning light,
–the coolant temperature warning light or warning message;
–the fault level 1 warning light (non-critical fault),
–the fault level 2 warning light (emergency stop),
–the OBD warning light (European On Board Diagnostic).
These five functions are represented by 4 or 5 warning lights and/or messages sent by the trip computer.
A 3 second visual inspection is carried out by the injection computer when ignition is switched on (automatic
procedure for test managed by the instrument panel).
Orange Pre-post heating/non-critical fault SERVICE warning light (level 1)
This light is used both as an in-operation indicator light and as a system fault indicator:
–Continuously lit with + after ignition feed:
Indicates preheating of the spark plugs.
–Continuous lighting accompanied by the message CHECK INJECTION or ELECTRONIC FAULT:
Indicates a level 1 fault (implies operation in injection system defect mode).
The driver should carry out repairs as soon as possible.
Temperature warning light/red EMERGENCY STOP (level 2)
This indicator light is used both as an in-operation indicator light and as a system fault warning light. Lights up for
3 seconds when the ignition is switched on (automatic test procedure managed by the instrument panel):
–Continuously lit or alternately lit with ENGINE OVERHEATING message:
Indicates engine overheating (the driver is free to choose whether or not to stop the vehicle).
–Continuously lit with the FAULTY INJECTION message:
Indicates a level 2 fault (In this case, the injection is automatically cut after a few seconds).
The driver should carry out repairs as soon as possible.
ORANGE OBD excess pollution warning light
An engine symbol accompanied by the message CHECK EMISSION CONTROL.
This warning light comes on if the system has one or more OBD faults.
This warning light is used to warn the driver of injection faults leading to excessive pollution or that the EOBD* system
has been deactivated.
The injection computer requests activation of the OBD warning light for a present fault only after three successive
driving cycles.
A 3 second visual inspection is carried out by the injection computer when ignition is switched on (automatic
procedure for test managed by the instrument panel).
*EOBD: Electronic on board diagnostics.

DIESEL INJECTION
Fault finding – System operation13B
13B - 15V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
EOBD* management:
The OBD (On Board Diagnostic) system enables the detection of any faults relating to the vehicle emission control
system (OBD EURO IV emission control standards exceeded).
This system should be active for the entire life of the vehicle.
1. Conditions causing an OBD fault
An OBD fault will be detected after 3 driving cycles and the following parameters will be registered in the computer:
–engine load,
–vehicle speed
–air temperature
–coolant temperature,
–turbocharging pressure,
–rail pressure,
–air flow,
–distance travelled in miles by the vehicle since activation of the OBD warning light.
It allows the driver to know whether the vehicle has a fault directly linked to the emission control system.
2. System faults indicated by the OBD
Only a few faults are indicated by the OBD system:
–DF001 Coolant temperature sensor circuit.
–DF003 Atmospheric pressure sensor circuit.
–DF011 Sensor feed voltage no. 1.
–DF012 Sensor feed voltage no. 2.
–DF013 Sensor feed voltage no. 3.
–DF038 Computer in 6.DEF EEPROM fault.
–DF040 Cylinder 1 injector circuit in CO Open circuit.
–DF041 Cylinder 2 injector circuit in CO Open circuit.
–DF042 Cylinder 3 injector circuit in CO Open circuit.
–DF043 Cylinder 4 injector circuit in CO Open circuit.
–DF054 Turbocharging solenoid valve control circuit in CC.0 Short circuit to earth.
–DF056 Air flow sensor circuit.
–DF209 EGR valve position sensor circuit.
–DF621 EGR valve jammed open.
Some repair operations require programming to ensure that certain engine components function correctly.
Follow the programming procedures (see Replacement of components), if replacing the exhaust gas
recirculation valve or an injector.
*EOBD: Electronic on board diagnostics

DIESEL INJECTION
Fault finding – System operation13B
13B - 16V3 MR-372-J84-13B250$135.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
3. Conditions for clearing an OBD fault
An OBD fault is cleared in several steps.
The fault present in the diagnostic tool is not stored (following repair) until after 3 trips with the vehicle.
The OBD warning light will only light up after these 3 driving cycles.
The warning light coming on does not always mean that there is a fault on the system.
In order that the OBD fault and the display parameters are cleared from the computer, the system needs to
go through 40 engine heating cycles.
An engine heating cycle is a driving cycle during which:
–the engine coolant temperature reaches at least 71.1 ˚C,
–the engine coolant temperature varies by 22.2 °C in relation to the engine starting temperature.
If one of these conditions is not fulfilled, the OBD fault will still be present or stored in the injection computer.