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-211
MR-372-J84-13B150$846.mif
V10
DIESEL INJECTION
Fault finding - Fault finding chart13B
ALP 7 Oil leaks from the turbocharger
NOTESBefore dealing with this customer complaint, check that there are no faults,
and the conformity (or otherwise) of the parameters and statuses using
the diagnostic tool.
If the customer complaint is not eliminated, perform the following checks.
Check the area around the turbocharger
Note:
An oil leak does not correspond always to a turbocharger fault, the oil leak can arise from the area around
the turbocharger.
Depending on the vehicle type, the best visual access will be either from above or from below.
1-Do not start the engine.
Check the area around the turbocharger and identify the origin of the leaks.
Clean the oil traces on the turbocharger.
2- Start the engine and let it warm up for several minutes.
IMPORTANT
If the air filter was removed previously, refit it before starting the engine (risks foreign matter entering the air inlet
circuit).
Accelerate with no load several times, progressively increasing the duration before releasing the accelerator
pedal.
Visually inspect the exterior condition of the fuel supply pipes and the turbocharger oil return and the area
around it.
Identify the origin of the leaks.
Is an oil leak present at the air compressor inlet or outlet?
YES
NO
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
EDC16_V44_ALP7 / EDC16_V48_ALP7 / EDC16_V4C_ALP7EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4C
13B-227
MR-372-J84-13B150$893.mif
V10
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4CDIESEL INJECTION
Fault finding - Tests13B
TEST 2 Turbocharger air chain
Check for an air filter.
Check the replacement frequency for the air filter in 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?
YES
Check the condition of the air filter.
Visually inspect the condition of the filter section of
the air filter.
Is the air filter or its seal damaged?
Is the air filter clogged (does it contain a lot of
impurities)?
NO
Low pressure circuit check
Note:
According to the vehicle type, maximum visual
access will either be from above or from below.
Visually inspect the condition of the following
components:
– fresh air inlet scoop on the front end panel of the
vehicle,
– air filter air inlet pipe,
– filter air pipe up to the compressor inlet,
– air flowmeter mountings.
Is one of these components incorrect
(disconnected, cut, bent, pierced or kinked
pipes)?
NO
NO
YES
Replace the air filter (see MR 364 (Mégane II)
or 370 (Scénic II), Mechanical, 12A, Fuel
mixture,
Air filter,
Removal - Refitting
).
YESReplace the defective parts (see MR 364
(Mégane II) or 370 (Scénic II), Mechanical,
12B, Turbocharging).
EDC16_V44_TEST2 / EDC16_V48_TEST2 / EDC16_V4C_TEST2
13B-229
MR-372-J84-13B150$893.mif
V10
13B
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4CDIESEL INJECTION
Fault finding - Tests
1
TEST5 Diesel fuel conformity check
WARNING
During this operation, it is essential to:
– refrain from smoking or bringing incandescent objects close to the work area,
– protect yourself against fuel splashes due to residual pressure in the pipes,
– wear safety goggles with side guards,
– wear leaktight gloves (Nitrile type).
IMPORTANT
– To avoid any corrosion or damage, protect the areas on which fuel is likely to run.
– To prevent impurities from entering the circuit, place protective plugs on all fuel circuit components
exposed to the open air.
Preparations:
Weigh an empty 1300 ml plastic cup (part no. 77 11 171 413) with its cover (part no. 77 11 171 416) using
electronic scales such as those used in body paint workshops (example: PANDA part no. 77 11 224 995).
Record the weight of the empty plastic cup.
This type of plastic cup is used to prepare paint.
Remove 1 L of fuel at the diesel filter outlet (see MR 364 (Mégane) or 370 (Scénic), Mechanical, 19C, Tank,
Fuel tank: Draining), using a pneumatic transfer pump (part no. 634-200) and place it in the 1300 ml plastic cup.
Cover the plastic cup with its cover and allow it to settle for approximately 2 minutes.
Is the fuel cloudy or does it
separate into two parts?Presence of water in diesel fuel, the fuel is not compliant.
Drain the fuel circuit, including the tank (see MR 364 (Mégane)
or 370 (Scénic), Mechanical, 19C, Tank, Fuel Tank:
Draining).
YES
NO
A
EDC16_V44_TEST5 / EDC16_V48_TEST5 / EDC16_V4C_TEST5
13B-236
DIESEL INJECTION
Fault finding - Glossary13B
V10 MR-372-J84-13B150$940.mif
EDC16 INJECTION
Program No.: C1
Vdiag No: 44, 48 and 4CDIESEL INJECTION
Fault finding - Glossary
(R = Resistance, EGR = Exhaust gas recirculation)Injection computer112-track (BOSCH)
Connectors: black A 32-track, brown B 48-track, grey C 32-track
Atmospheric pressure sensorIntegrated into the computer (BOSCH)
Injector0.33Ω at + 20°C / 2Ω max (BOSCH)
1350 bar
Flow regulator (high pressure
pump)R= 3Ω at + 20°C (BOSCH, CP3.2+ pump type)
Rail pressure sensorRail pressure limiter: opening at around 1600 bar
(BOSCH, bolted to the rail)
Engine speed sensorR = 680 ± 170Ω at + 20°C (MGI)
Camshaft sensorHall effect sensor (ELECTRICFIL)
R = 10250 ± 500Ω at + 20°C (measurement between tracks 2 and 3
of the sensor)
Turbocharger control solenoid
valve15.4 ± 0.7Ω at + 20°C (PIERBURG)
Electric EGR valveTrack 1: + 12 V solenoid
Track 2: + 5 V potentiometer
Track 3: Not usedTrack 4: potentiometer earth
Track 5: solenoid earth
Track 6: potentiometer signal
SOLENOID: R between tracks 1 and 5 = 8 ± 0.5Ω at + 20°C
POTENTIOMETER: R between tracks 2 and 4: 4 ± 2 kΩ at + 20°C
(Pierburg)
EGR by-pass solenoid valveR= 46 ±3Ω at + 25°C
(EATON/BITRON)
Electric damper valveDIRECT CURRENT MOTOR
(VDO)
Air flowmeterTrack 1: air temperature signal
Track 2: flow sensor earth
Track 3: + 5 V flowmeterTrack 4: + 12 V battery
Track 5: air flow signal
Track 6: battery earth
(SIEMENS)
Air temperature sensorR = 3714Ω ± 161 at + 10°C/2448Ω ± 96 at + 20°C/1671Ω ± 59 at
+30°C
Coolant temperature sensorR = 2252Ω ± 112 at 25°C/811Ω ± 39 at 50°C/283Ω ±8 at 80°C
Fuel temperature sensorR = 2051Ω ± 123 at 25°C/810Ω ± 47 ± at 50°C/309Ω ± 17 at 80°C
Accelerator pedal sensorR gang 1 = 1700 ± 900Ω
R gang 2 = 2850 ± 2050Ω
Heater plugR= 0.6Ω at + 20°C/2Ω max
Maximum current drawn: 28 A at 0 seconds/12 A at 10 seconds/9 A after
30 seconds
Diesel fuel temperature sensorAccording to application (ZERTAN)
MR-372-J84-13B150$940.mif