13B - 2
DIESEL INJECTION
Fault finding - Introduction13B
V10 MR-372-J84-13B150$047.mif
113B
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4CDIESEL INJECTION
Fault finding - Introduction
1. SCOPE OF THIS DOCUMENT
This document presents the fault finding procedure applicable to all computers with the following specifications:
2. PREREQUISITES FOR FAULT FINDING
Documentation type
Fault finding procedures (this manual):
– Assisted fault finding (integrated into the diagnostic tool), Dialogys.
Wiring diagrams:
– Visu-Schéma (CD-ROM), paper.
Type of diagnostic tools
–CLIP
Special tooling required
3. RECAP
Procedure
To save energy, the UCH of the vehicle interrupts the + after ignition feed after 3 minutes.
To carry out fault finding on the vehicle's computers, switch the ignition to fault finding mode (forced + after ignition).
Proceed as follows:
– with the vehicle card in the card reader,
– press and hold start button (longer than 5 seconds) with start-up conditions not fulfilled,
– connect the diagnostic tool and perform the required operations.
To cut off + after ignition, proceed as follows:
– disconnect the diagnostic tool,
– vehicle card in reader,
– press the Start button twice briefly (less than 3 seconds),
– Check that the + after ignition feed has been cut off by checking that the computer warning lights on the
instrument panel have gone out. Vehicle(s): Mégane II, Scénic II
Engine type and suffix: F9Q 800, 808, 812
Function concerned: Diesel injectionComputer name: Diesel injection
Program no.: C1
VDIAG No.: 44, 48 and 4C
Special tooling required
Multimeter
Elé. 1590Computer connection unit
Elé. 1681Universal unit
Note:
The left-hand and right-hand xenon bulb computers are powered when the dipped headlights are lit. Fault finding
procedures can only be carried out on them after the ignition has been switched on in fault finding mode (forced +
after ignition) and the dipped headlights are lit.
EDC16_V44_PRELI/EDC16_V4C_PRELI/EDC16_V48_PRELI
MR-372-J84-13B150$047.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-26
DIESEL INJECTION
Fault finding - Interpretation of faults13B
V10 MR-372-J84-13B150$282.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4CDIESEL INJECTION
Fault finding - Interpretation of faults
DF001
PRESENT
OR
STOREDCOOLANT TEMPERATURE SENSOR CIRCUIT
CC.0 : short circuit to earth
CO.1 : open circuit or short circuit to + 12 V
NOTESConditions for applying the fault finding procedure to stored faults:
The fault is declared present with the engine running or following a road test.
Special notes:
If the fault is present:
– the coolant temperature: PR064: Coolant temperature is fixed at 119°C,
– the preheating phase is greater than 10 seconds,
– the fan assembly is permanently supplied,
The level 1 warning light comes on.
Use bornier Elé. 1681 for any work on the computer connectors.
CC.0
NOTESNone.
Check the coolant temperature sensor connections.
Repair if necessary.
Measure the resistance of the coolant temperature sensor between terminals 2 and 3 of its black connector.
Replace the sensor if its resistance is not approximately: 12460±112Ω at -10°C
2252±112Ω at 25°C
811.4±39Ω at 50°C
283±8Ω at 80°C
115±3Ω at 110°C
Check the injection computer connections.
Check for continuity and the absence of interference resistance of the following connections:
Injection computer brown 48-track connector B, track F2 Track 3 coolant temperature sensor
Injection computer brown 48-track connector B, track H1 Track 2 coolant temperature sensor
Repair if necessary.
If the fault is still present, replace the coolant temperature sensor.
AFTER REPAIRDeal with any faults.
Carry out a road test followed by a check with the diagnostic tool.
EDC16_V44_DF001/EDC16_V48_DF001/EDC16_V4C_DF001
MR-372-J84-13B150$282.mif
13B-28
DIESEL INJECTION
Fault finding - Interpretation of faults13B
V10 MR-372-J84-13B150$282.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
DF003
PRESENT
OR
STOREDATMOSPHERIC PRESSURE SENSOR CIRCUIT
1.DEF : Signal outside upper limit
2.DEF : signal outside lower limit
3.DEF : inconsistent signal
NOTESConditions for applying the fault finding procedure to stored faults:
The fault is declared present after:
–the engine is started,
–a road test.
Special notes:
The atmospheric pressure sensor is integrated into the injection computer and cannot
be separated.
If the fault is present:
– there is light smoke,
– the atmospheric pressure value changes to default mode, PR035 Atmospheric
pressure = 750 mbar,
–the level 1 warning light is lit.
Use bornier Elé. 1681 for any work on the computer connectors.
Disconnect the injection computer and check the condition of the contacts and connector.
Repair if necessary.
Display the value of parameter PR041 Turbocharging pressure.
If this value is stuck at 750 mbar, refer to interpretation of fault DF004 Turbocharging pressure sensor
circuit.
If the fault is still present, contact the Techline.
AFTER REPAIRDeal with any faults.
Carry out a road test followed by a check with the diagnostic tool.
EDC16_V44_DF003/EDC16_V48_DF003/EDC16_V4C_DF003
13B-29
DIESEL INJECTION
Fault finding - Interpretation of faults13B
V10 MR-372-J84-13B150$282.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
DF004
PRESENT
OR
STOREDTURBOCHARGING PRESSURE SENSOR CIRCUIT
CO.0 : open circuit or short circuit to earth
CC.1 : short circuit to + 12 V
1.DEF : signal incoherence
NOTESOrder of priority in the event of more than one fault:
In the event of a combination of faults DF004 and DF011 Sensor supply voltage
no.1, deal with fault DF011 first.
Conditions for applying the fault finding procedure to a stored fault:
The fault is declared present after starting the engine, or during a road test.
Special notes:
Use bornier Elé. 1681 for all operations on the injection computer connectors.
If the fault is present:
– the EGR function is inhibited,
– the turbocharging pressure sensor is in defect mode, PR041 = 750 mbar,
– the intake air temperature is in defect mode, PR059 = 25°C.
The level 1 warning light comes on.
CO.0
NOTESNone.
Check the turbocharger pressure sensor connections.
Check the injection computer connections.
Repair if necessary.
Check the continuity and insulation from earth of the following connections:
Injection computer brown 48-track connector B, track K2 Track 3 turbocharger pressure
sensor connector
Injection computer brown 48-track connector B, track G4 Track 1 turbocharger pressure
sensor connector
Repair if necessary.
If the fault is still present, replace the turbocharging pressure sensor.
AFTER REPAIRDeal with any faults.
Carry out a road test followed by a check with the diagnostic tool.
EDC16_V44_DF004/EDC16_V48_DF004/EDC16_V4C_DF004
13B-31
DIESEL INJECTION
Fault finding - Interpretation of faults13B
V10 MR-372-J84-13B150$282.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
DF005
PRESENT
OR
STOREDENGINE SPEED SENSOR CIRCUIT
1.DEF : no signal
2.DEF : signal incoherence
NOTESConditions for applying the fault finding procedure to stored faults:
The fault is declared present:
– when an attempt is made to start the engine,
– when the engine is running.
Special notes:
Use bornier Elé. 1681 for any work on the computer connectors.
The engine speed sensor is consistent with the camshaft sensor.
If the fault is present, the level 2 warning light comes on.
Check the engine speed sensor connections.
Repair if necessary.
Check that the sensor is correctly mounted and that the flywheel target is not damaged.
Check that the gap between the engine speed sensor and the engine flywheel is 0.5 to 1.8 mm.
Check the resistance of the engine speed sensor between terminals A and B of the black connector.
The winding resistance is between 510 and 850 Ohm at an engine temperature of 20°C.
If the value displayed is incorrect, replace the engine speed sensor.
Check the injection computer connections.
Repair if necessary.
Check the continuity and the absence of interference resistance of the following connections:
Injection computer 48-track brown connector B, track B1 Track A engine speed sensor
Injection computer 48-track brown connector B, track C1 Track B engine speed sensor
Repair if necessary.
If the fault is still present, contact the Techline.
AFTER REPAIRDeal with any faults.
Carry out a road test followed by a check with the diagnostic tool.
EDC16_V44_DF005/EDC16_V48_DF005/EDC16_V4C_DF005
13B-32
DIESEL INJECTION
Fault finding - Interpretation of faults13B
V10 MR-372-J84-13B150$282.mif
EDC16 INJECTION
Program No.: C1
Vdiag No.: 44, 48 and 4C
DF007
PRESENT
OR
STOREDRAIL PRESSURE SENSOR CIRCUIT
CC.0 : short circuit to earth
CO.1 : open circuit or short circuit to + 12 V
1.DEF : offset at minimum threshold
2.DEF : offset at maximum threshold
NOTESPriorities when dealing with a number of faults:
Deal with fault DF013 Sensor supply voltage no. 3 first, if it is present or stored.
Conditions for applying the fault finding procedure to stored faults:
The fault is declared present after repeated engine starts or with the engine running.
Special notes:
Use bornier Elé. 1681 for any work on the computer connectors.
If the fault is present, the engine stops immediately.
The level 2 fault warning light will be lit.
CC.0
NOTESNone.
Check the rail pressure sensor connectors.
Check the injection computer connections.
Repair if necessary.
Check the continuity and insulation against earth of the following connections:
Injection computer brown 48-track connector B, track G3 Track 2 rail pressure sensor
Injection computer brown 48-track connector B, track A4 Track 3 rail pressure sensor
Repair if necessary.
If the fault is still present, replace the rail pressure sensor and tighten it to 35 ± 5 N.m.
Observe the safety instructions in the Introduction.
AFTER REPAIRDeal with any faults.
Carry out a road test followed by a check with the diagnostic tool.
EDC16_V44_DF007/EDC16_V48_DF007/EDC16_V4C_DF007