13B-3
MR-372-J84-13B200$036.mif
V13
DIESEL INJECTION
Fault finding – Introduction
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
Faults
Faults are declared as either present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but have not been diagnosed within the current context).
The present or stored status of faults should be taken into consideration when the diagnostic tool is switched on
after the + after ignition feed (without any system components being active).
For a present fault, apply the procedure described in the Interpretation of faults section.
For a stored fault, note the faults displayed and apply the instructions in the Notes section.
If the fault is confirmed when the instructions in the Notes section are applied, the fault is present. Deal with the
fault
If the fault is not confirmed, check:
– the electrical connections that correspond to the fault,
– the connectors for this connection,
– the resistance of the component detected as faulty,
– the condition of the wires.
Refer to paragraphs 3.1 Checking the wiring and 3.2 Checking the connectors.
Conformity check
The aim of the conformity check is to check data that does not produce a fault on the diagnostic tool because the
data is inconsistent. Therefore, this stage is used to:
– carry out fault finding on faults that do not have a fault display, and which may correspond to a customer
complaint.
– check that the system is operating correctly and that there is no risk of a fault recurring after repairs.
This section gives the fault finding procedures for statuses and parameters and the conditions for checking them.
If a status is not behaving normally or a parameter is outside the permitted tolerance values, consult the
corresponding fault finding page.
Customer complaints – Fault finding chart
If the test with the diagnostic tool is OK but the customer complaint is still present, the fault should be processed by
customer complaints.
A summary of the overall procedure to follow is provided on the following page in the
form of a flow chart.
13B-4
MR-372-J84-13B200$036.mif
V13
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5CDIESEL INJECTION
Fault finding – Introduction13B
3. FAULT FINDING PROCEDURE
* Check the battery charge, the condition of the fuses and the level of the fuel in the tank.
Perform a pre-diagnostic on the
system
Print the system fault finding log
(available on CLIP and in the
Workshop Repair Manual or
Technical Note)
Connect CLIP
no
Dialogue with
computer?
yes
Read the faults
no
Faults
present
yes
Deal with present faults
Deal with stored faults
no
The cause is
still presentFault
solved
yes
See ALP no. 1
Conformity check
no
The cause is
still presentFault
solved
Use fault finding charts
(ALPs)
no
The cause is
still presentFault
solved
Contact the Techline with the
completed fault finding log
13B-9
MR-372-J84-13B200$072.mif
V13
13B
DIESEL INJECTION
Fault finding – Cleanliness guidelines
I - HAZARDS ASSOCIATED WITH CONTAMINATION
The high pressure direct injection system is highly sensitive to contamination. 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 have entered the system during dismantling.
The cleanliness principle must be applied from the filter to the injectors.
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.
II - INSTRUCTIONS TO BE FOLLOWED PRIOR TO ALL OPERATIONS
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.
Check that you have hermetically resealable plastic bags for storing removed parts. Parts stored in this way will be
less susceptible to the risk of contamination. The bags are to be used once only, and discarded after use. IMPORTANT
Cleaning the engine using a high pressure washer is prohibited because of the risk of damaging connections.
In addition, moisture may collect in the connectors and create electrical connection faults.
IMPORTANT
Before any work is carried out on the high pressure injection system, protect:
– the accessories and timing belts,
– the electrical accessories, (starter, alternator, electric power-assisted steering pump),
– the flywheel surface, to prevent any diesel from running onto the clutch friction plate.
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
MR-372-J84-13B200$072.mif
13B-10
MR-372-J84-13B200$072.mif
V13
DIESEL INJECTION
Fault finding – Cleanliness guidelines
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
Use lint-free cleaning cloths (cloth part number 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, the parts, unions and injection system zones).
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.
III - 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. The plugs must not be reused under any circumstances.
Seal the pouch shut, even if it has to be opened shortly afterwards. Ambient air carries contamination.
All components removed from the injection system must be stored in a hermetically sealed plastic bag once they
have been plugged.
Using a brush, cleaning agent, air gun, sponge or normal cloth is strictly prohibited once the circuit has been
opened. These items could allow contamination to enter the system.
A new component replacing an old one must not be removed from its packaging until it is to be fitted to the vehicle.
13B-12
MR-372-J84-13B200$108.mif
V13
DIESEL INJECTION
Fault finding – System operation
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
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.
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 (EGR),
– fuel supply check (advance, flow and rail pressure),
– the fan assembly control,
– the air conditioning (cold loop function),
– the cruise control/speed limiter function,
– pre-post heating control,
– indicator lights control via the multiplex network,
– the operation of the catalysed particle filter.
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 flow actuator allows the high pressure
pump to supply the exact quantity of diesel fuel required to maintain the pressure in the rail. 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-14
MR-372-J84-13B200$108.mif
V13
DIESEL INJECTION
Fault finding – System operation
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
c) Functions hosted:
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 (Mégane II only):
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 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.
– a "valving" function depending on the various engine functions: the damper valve closes by a few % in order to
create a venturi effect in the EGR valve flow section.
The aim of this is to accelerate the EGR gas flow rate and to reduce the emission of pollutants.
– regulatory function during the regeneration of the particle filter.
Thermoplunger management (only for Vdiag 58, 5C,18, 1C and 20):
This vehicle is fitted with thermoplungers. They are managed and activated by the injection system.
See configuration reading LC056 Thermoplungers: WITH or WITHOUT.
When necessary, the thermoplungers are actuated by the injection system only during particle filter
regeneration by means of a specific unit.
The maximum number of thermoplungers that can be managed is four; their activation depends mainly on the
coolant temperature (< 15°C) and air temperature (< 5°C).
13B-16
MR-372-J84-13B200$108.mif
V13
DIESEL INJECTION
Fault finding – System operation
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
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.
Catalysed particle filter management:
The particle filter prevents the escape of carbon particles emitted by the engine but not yet removed from the
exhaust gases.
The particle filter is a microporous structure containing channels arranged so as to force-filter the exhaust gases.
The exhaust system consists of several components:
– an oxidation catalytic converter mounted after the turbocharger. This catalytic converter ensures that HC/CO
levels meet current standards by generating the heat (rise in exhaust temperature caused by catalysis) required
for particle filter regeneration,
– a catalysed particle filter located under the bodywork;
– A differential pressure sensor to inform the computer about the pressures upstream and downstream of the
particle filter and a temperature sensor upstream and downstream of the particle filter,
– a turbine upstream temperature sensor.
As the vehicle is being driven, the particle filter gets loaded with particles (soot). Using a given weight of soot
determined by computer mapping, regeneration mode can be triggered when the maximum weight of soot in the
particle filter is reached and the correct engine operating conditions are met (coolant temperature, etc.).
Particle filter regeneration consists of burning the particles of soot that have accumulated in the filter.
The differential pressure sensor measures the particle filter inlet/outlet pressure difference, this value makes it
possible to calculate the weight of soot present in the particle filter using computer mapping: (soot weight = pressure
differential depending on the exhaust volume flow rate).
If all the criteria are met, the computer enters regeneration mode. The injection programming is then adjusted in
order to raise the target exhaust gas temperature between 550 and 650°C.
This temperature allows the particles accumulated in the filter to be partially or completely burnt (regenerated).
Regeneration efficiency depends on the particle filter inlet temperature and the time spent in regeneration mode.
Regeneration may be automatically triggered when driving if the soot content is below:
Vdiag 58 and 5C: 74 g for Scénic II F9Q804
66 g for Mégane II F9Q804
66 g for Scénic F9Q803
Vdiag 50: 45 g for Scénic II and Mégane II
If the weight of soot is greater than the values above or if regeneration when driving has not been carried out, the
user will have to request an After-Sales regeneration.
Regeneration may be carried out automatically when driving if the weight of soot is less than 56 g and if the number
of regeneration attempts when driving is less than 10 (only for Vdiag 1C and 20).
13B-18
MR-372-J84-13B200$108.mif
V13
DIESEL INJECTION
Fault finding – System operation
EDC16
Program No: C1
Vdiag No: 18, 1C, 20,
50, 58, 5C
13B
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. It lights up for
3 seconds after the ignition is switched on (automatic test procedure managed by the instrument panel):
– Continuously or intermittently lit, accompanied by the message Engine overheating:
Indicates engine overheating (the driver is free to choose whether or not to stop the vehicle).
–For Vdiag 50, 58 and 5C: continuously lit, accompanied by the message faulty injection:
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.
–For Vdiag 18, 1C and 20: continuously lit, accompanied by the message Injection fault: stop the engine and by
a bleep, this indicates a level 2 fault.
In that case, the vehicle must be stopped immediately (when traffic conditions allow).
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 alert the driver of any injection faults that could lead to excessive pollution, or if the
EOBD system has been deactivated.
The injection computer requests illumination of the OBD warning light for a present fault only after three consecutive
driving cycles.
If it flashes, reduce the engine speed until the flashing stops.
The driver should carry out repairs as soon as possible.
The 3 second visual inspection when the ignition is switched on (automatic test procedure managed by the
instrument panel) is carried out by the injection computer.
Special particle filter ORANGE warning light or warning message (depending on instrument panel)
– Vdiag 50, 58, 5C:
This warning light or message is used to warn the driver that the particle filter is clogged or a significant number of
failed regenerations while driving due to driving conditions not being favourable for regeneration.
Table of thresholds:
EnginePR383 Weight of soot in the
particle filterPR848 Number of failed
regenerations
Scénic II Mégane IIScénic II Mégane II
F9Q804 Vdiag 5035 35 3
F9Q803 Vdiag 58 and 5C50
7
F9Q804 Vdiag 58 and 5C58 50 7