13B - 6
DIESEL INJECTION
Fault finding - Introduction13B
V10 MR-372-J84-13B150$047.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
5. FAULT FINDING LOG
You will always be asked for this log:
– when requesting technical assistance from Techline,
– for approval requests when replacing parts for which approval is mandatory,
– 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 ADVICE
Safety rules must be observed whenever work is carried out on a component to prevent physical damage or human
injury:
– check the battery voltage to avoid incorrect operation of computer functions,
– use the proper tools.
7. CLEANLINESS ADVICE THAT MUST BE OBSERVED WHEN WORKING ON THE HIGH PRESSURE DIRECT
INJECTION SYSTEM
Risks relating to contamination
The system is highly sensitive to contamination. The risks caused by the introduction of contamination are:
– damage or destruction to the high pressure injection system and the engine,
– a component seizing or leaking.
All After-Sales operations must be performed under very clean conditions. Performing an operation in a very clean
environment means that no impurities (particles only a few microns in size) will have been able to enter the system
during dismantling or into the circuits via the fuel unions.
The cleanliness principle must be applied from the filter to the injectors.IMPORTANTIMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools. The
FAULT FINDING LOG, which should be completed during the procedure, enables you to keep
track of the procedure which is carried out. It is an essential document when consulting the
manufacturer.
IT IS THEREFORE MANDATORY TO FILL OUT A FAULT FINDING LOG FOR EACH FAULT
FINDING PROCEDURE.
13B - 7
DIESEL INJECTION
Fault finding - Introduction13B
V10 MR-372-J84-13B150$047.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
7. CLEANLINESS ADVICE THAT MUST BE OBSERVED WHEN WORKING ON THE HIGH PRESSURE DIRECT
INJECTION SYSTEM
Risks relating to contamination
The direct injection system is very sensitive to pollution. 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 enter the system during dismantling.
The cleanliness principle must be applied from the filter to the injectors.
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.
What are the sources of contamination?
– metal or plastic swarf,
– paint,
– fibres: from cardboard
from brushes,
from paper,
from clothing,
from cloths.
– foreign bodies such as hair,
– ambient air,
–etc.
IMPORTANT
It is not possible to clean the engine using a high pressure washer because of the risk of damaging connections.
In addition, moisture may collect in the connectors and create electrical connection faults.
13B - 8
DIESEL INJECTION
Fault finding - Introduction13B
V10 MR-372-J84-13B150$047.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
Instructions to be followed before any work is carried out on the injection system:
Protect the accessories and timing belts, the electrical accessories (starter, alternator, electric power-assisted
steering pump) and the mating face to prevent diesel fuel spilling onto the clutch friction plate.
Check that you have plugs for the unions to be opened (set of plugs available from the Parts Department). The plugs
are single-use only. After use, they must be discarded (once used they are soiled and cleaning is not sufficient to
make them reusable). Unused plugs must be discarded.
Ensure that you have hermetically resealable plastic bags for storing removed parts. There is less risk of parts
stored in this way being exposed to contamination. These are single-use bags; after use they must be discarded.
Use lint-free cleaning cloths (part no. 77 11 211 707). Using normal cloth or paper is prohibited. They are not lint-free
and could contaminate the fuel circuit. Each cloth should only be used once.
Use fresh cleaning agent for each operation (used cleaning agent is contaminated). Pour it into an uncontaminated
container.
For each operation, use a clean brush in good condition (the brush must not shed its bristles).
Use a brush and cleaning agent to clean the unions to be opened.
Blast compressed air over the cleaned parts (tools, workbench, and the parts, unions and injection system area).
Check that no bristles remain.
Wash your hands before and during the operation if necessary.
When wearing leather protective gloves cover them with latex gloves to prevent contamination.
Instructions to be followed during the operation
As soon as the circuit is open, all openings must be plugged to prevent impurities from entering the system. The
plugs to be used are available from the Parts Department. They must not be reused under any circumstances.
Close the hermetically sealed bag, even if it has to be reopened shortly afterwards. Ambient air carries impurities.
All components removed from the injection system must be stored in a hermetically sealed plastic bag once they
have been plugged.
Using a brush, thinner, air gun, rifle-type brush or normal rag is strictly prohibited once the circuit has been opened.
These items are likely to allow impurities to enter the system.
If a component is being replaced with a new component, do not remove the packaging until it is ready to be fitted to
the vehicle.
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 - 18
DIESEL INJECTION
Fault finding - Allocation of computer tracks13B
V10 MR-372-J84-13B150$141.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
2 - Brown connector B, 48-track 2 - Brown connector B, 48-track (continued)
Track Description
A1 Camshaft sensor earth
A2 Not used
A3 Not used
A4 Fuel rail pressure sensor supply
B1 TDC sensor supply signal
B2 Not used
B3 Not used
B4 Air flow sensor supply
C1 TDC sensor earth signal
C2 Not used
C3 Not used
C4 Fuel rail pressure sensor earth
D1 Camshaft sensor signal
D2 Not used
D3 Not used
D4 Turbocharging pressure sensor earth
E1 Injection locking relay coil earth control
E2 Air flow sensor earth signal
E3 Not used
E4 Not used
F1 Refrigerant pressure sensor signal
F2 Coolant temperature sensor supply signal
F3 Refrigerant pressure sensor supply
F4 EGR valve position sensor supply
G1 Air flow sensor supply signal
G2 Air temperature signal
G3 Fuel rail pressure sensor signal
G4 Turbocharging pressure sensor supply
Track Description
H1 Injection coolant temperature sensor earth
H2 Fuel temperature signal
H3 Not used
H4 Not used
J1 Not used
J2 Gas recirculation potentiometer signal
J3 Not used
J4 Inlet flap solenoid valve control
K1 Not used
K2 Turbocharging pressure sensor signal
K3 Not used
K4 Not used
L1 Not used
L2 Gas recirculation solenoid valve control
L3 Not used
L4 Flow sensor earth
M1 Not used
M2 UPC supply
M3 Not used
M4 Fuel pressure regulation solenoid valve
control
13B - 19
DIESEL INJECTION
Fault finding - Allocation of computer tracks13B
V10 MR-372-J84-13B150$141.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
3 - Grey connector C, 32-track
Track Description
A1 Not used
A2 Water in diesel detection sensor signal
A3 Not used
A4 Preheating relay fault finding signal
B1 Not used
B2 Not used
B3 Not used
B4 Not used
C1 Not used
C2 EGR solenoid valve earth
C3 Refrigerant pressure sensor earth
C4 Not used
D1 Not used
D2 Not used
D3 Not used
D4 Not used
E1 Turbocharging pressure solenoid valve
control
E2 Preheating relay control
E3 Not used
E4 Not used
F1 Fuel temperature earth
F2 Not used
F3 Not used
F4 Not used
G1 Injector 4 control
G2 Injector 2 control
G3 Injector 1 earth
G4 Injector 2 earth
H1 Injector 1 control
H2 Injector 3 control
H3 Injector 4 earth
H4 Injector 3 earth