2011 RENAULT SCENIC Engine And Peripherals EDC16 Injection Workshop Manual

13B - 9
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4CDIESEL INJECTION
Fault finding - System operation
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 EDC16C3 type computer.
The system comprises:
– a diesel filter,
– a high pressure pump with an integrated low pressure pump (transfer pump),
– a high pressure regulator mounted on the pump,
– an injection rail,
– a diesel fuel pressure sensor integrated into the rail,
– four solenoid injectors,
– a diesel fuel temperature sensor,
– a coolant temperature sensor,
– an upstream air temperature sensor,
– a cylinder reference sensor,
– an engine speed sensor,
– a turbocharging pressure sensor,
– an accelerator pedal potentiometer,
– an EGR solenoid valve,
– an atmospheric pressure sensor integrated into the injection computer,
– an air flow sensor,
– a turbocharging pressure limitation solenoid valve,
– a damper flap solenoid valve.
The common rail direct high pressure injection system works sequentially (based on the petrol engine multipoint
injection function).
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 injection 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-J84-13B150$094.mif

13B - 10
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
a) The computer
– Determines the value of injection pressure necessary for the engine to operate correctly 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.
– It determines the injection timing required to deliver the right quantity of diesel fuel and the moment when injection
should start.
– Controls each injector electrically and individually after determining these two 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,
– fuel supply check (advance, flow and rail pressure),
– the fan assembly via the Protection and Switching Unit (centralised coolant temperature management
function),
– the air conditioning (cold loop function),
– the cruise control/speed limiter function,
– the pre-postheating control.
– the 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 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.

13B - 11
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
Multiplex connection between the vehicle's various computers
The Mégane II electronic system is a multiplex network. 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,
– the vehicle speed signal is transmitted by the ABS-ESP computer via the multiplex network.
The system can inject diesel fuel into the engine at a pressure of up to 1350 bar. Before each operation, check that
the injection rail is depressurised and that the fuel temperature is not too high.
When working on the high pressure injection system, you must follow the cleanliness guidelines and safety advice
specified in this document.
Removal of the internal parts of the pump and injectors is prohibited. Only the fuel flow actuator, the diesel fuel
temperature sensor and the air vent unit 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 strictly prohibited 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. IMPORTANT
The engine must not operate with:
– Diesel fuel containing more than 10 % diester,
– Petrol, even in tiny quantities.

13B - 12
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
b) Functions included
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 transition phases (e.g. high acceleration demand for overtaking, anti-stalling and moving off). These
conditions are only taken into account if they do not occur repeatedly, so as to prevent system instabilities (erratic
deactivation),
– when certain faults appear.
Cold loop air conditioning management
The air conditioning is cold loop managed, 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 fan assembly, from the UPC, according to the vehicle speed, the refrigerant pressure
and the engine coolant temperature.

13B - 13
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
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
When activated, the cruise control function maintains the vehicle at a preselected speed, regardless of the driving
conditions encountered.
If the driver wishes to exceed the cruising speed, they may:
– depress the accelerator pedal and exceed the cruising speed (the vehicle will return to the initial
cruising speed once the driver takes their 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.
It is possible to reactivate the vehicle speed control and resume the last cruising speed after deactivation (computer
supply not cut off).
The vehicle speed limiter function enables, when it is active (switch turned on), the vehicle speed to be limited to
a preselected value. The driver controls the vehicle in the normal way using the accelerator pedal until the limit
speed is reached.
If the driver wishes to exceed the cruising speed, they 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:
– by using 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.

13B - 14
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
c) Warning light management
Instrument panel display
The computer manages the data display on the instrument panel relating to engine operation. This involves
5 functions:
– the OBD warning light (European On Board Diagnostic),
– pre/postheating warning light,
– the coolant temperature warning light,
– the fault level 1 warning light (non-critical fault),
– the fault level 2 warning light (stop immediately).
These five functions are represented by 3 warning lights or messages sent by the trip computer.
Pre/postheating indicator light
This warning light is used both as an in operation indicator light and as a system fault indicator:
– continuously lit under + after ignition feed: indicates that the heater plugs are operating,
– continuously lit with injection faulty: indicates a level 1 fault (involves injection system operating in defect
mode. The user must carry out repairs as soon as possible).
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 lights up for
3 seconds after the ignition is switched on (automatic test procedure managed by the instrument panel).
– continuously lit: indicates engine overheating (the driver remains free to stop the vehicle or not),
– continuously lit, with the Engine stop message: indicates a level 2 fault (In this case injection is
automatically shut off after a few seconds).
Excess pollution OBD orange warning light
An engine symbol lights up for approximately 3 seconds when the engine is switched on.
For the Vdiag 44 and 48, it only lights up when the engine is running.
In Vdiag 4C, this warning light comes on if the system has one or more OBD faults.

13B - 15
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
d) OBD management
The OBD (On Board Diagnostic) system enables 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 operating cycles, and the following parameters will be saved in the calculator:
– engine load,
– vehicle speed,
– air temperature,
– coolant temperature,
– turbocharging pressure,
– rail pressure,
–air flow,
– vehicle mileage.
It allows the driver to know whether their 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:
–DF012 Sensor supply voltage no. 2.
–DF038 Computer.
–DF040 Cylinder 1 injector circuit.
–DF041 Cylinder 2 injector circuit.
–DF042 Cylinder 3 injector circuit.
–DF043 Cylinder 4 injector circuit.
–DF209 EGR valve position sensor circuit.
–DF272 EGR valve control circuit.
–DF621 EGR valve jammed open.
Some repair operations require programming to ensure that certain engine components function correctly.
Follow the programming procedures (described in the component replacement section), if replacing an
exhaust gas recirculation valve or an injector.

13B - 16
DIESEL INJECTION
Fault finding - System operation13B
V10 MR-372-J84-13B150$094.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
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 goes
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.