Page 388 of 431

13B-388
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP5 Irregular engine operation
NOTESBefore analysing 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.
If the engine races during gear changes, if there is a floor carpet, check that this is not blocking the accelerator
pedal, the brake pedal and the clutch pedal, then check the conformity of the clutch switch and the conformity of
the accelerator pedal sensor when the pedal is released.
Measure the resistance of the engine speed sensor between the following connections:
– Connection code 3BG,
– Connection code 3BL,
of component 149.
Replace the sensor if the resistance is not 200 Ω to 270 Ω at +20°C
Check the continuity of the following connections:
– Connection code 3BG,
– Connection code 3BL,
between components120 and 149.
Check the conformity of the engine earths (oxidation, tightness, etc.).
Check the mounting and condition (overheating) of the sensor.
Replace if necessary.
Check the low pressure circuit, run test 3 Low pressure circuit check.
Apply the air flow test procedure (see Interpretation of statuses and Interpretation of parameters).
Check the turbocharger, apply the following tests:
– test 2: Air path at the turbocharger,
– test 6: Turbocharger control solenoid valve check,
– test 7: Turbocharger.
Test the high pressure fuel circuit:
Run scenario SC035 High pressure fuel circuit fault finding (see Interpretation of commands).
If the customer complaint is still present, contact Techline.
EDC16C36_V44_ALP05/EDC16C36_V4C_ALP05/EDC16C36_V48_ALP05/EDC16C36_V50_ALP05/EDC16C36_V54_ALP05/
EDC16C36_V58_ALP05EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 389 of 431

13B-389
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP6 External leaks from the fuel circuit
NOTESBefore analysing 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.
IMPORTANT
Please observe the cleanliness guidelines and safety advice.
Procedure for checking for an external leak on the fuel circuit:
Clean away traces of grease with clean thinner and wipe the part or parts concerned with cleaning cloths.
Start the engine and increase the engine temperature until the diesel fuel reaches 40/50°C.
Stop the engine and check for traces of grease on the part or parts concerned.
If this is the case, replace the part or parts concerned.
Bleed the fuel circuit and continue the checks.
Does the priming bulb show traces of grease?
(Visual and tactile inspections)
Check the assembly of the components and the
condition of the seal at the union of the two
components, if the leak is at the seal.
Replace the part or the parts concerned.
Bleed the fuel circuit and continue the checks.
Check the counter pressure valve located on the
fuel return line, after the injectors. Does the diesel filter show traces of grease?
(Visual and tactile inspections)
Do the fuel return pipes show traces of grease?
(Visual and tactile inspections)
YES
NO
YES
NO
YES
A
EDC16C36_V44_ALP06/EDC16C36_V4C_ALP06/EDC16C36_V48_ALP06/EDC16C36_V50_ALP06/EDC16C36_V54_ALP06/
EDC16C36_V58_ALP06EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 391 of 431

13B-391
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP7 Rough idle
NOTESBefore analysing 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 sealing and condition of the inlet circuit by running Test 4 Turbocharged air circuit check.
Check the low pressure circuit
check the engine parameters:
– Check the update of the engine management computer calibration (last calibration).
– Check the conformity of the IMA codes (using the Identification screen on the Clip diagnostic tool).
– Check the charging circuit (see Technical Note 6014A Checking the charging circuit)
– To check the conformity of the engine speed signal, check:
– The wiring.
– The flywheel position and the condition of the flywheel teeth.
– The position and tightness of the engine speed sensor.
– Check the fuel flow correction from station to station, run Test 10 Poor injector operation.
Check the connections and wiring of the injectors.
Check the connections and wiring of the engine management computer to the injectors.
Repair if necessary.
A
EDC16C36_V44_ALP07/EDC16C36_V4C_ALP07/EDC16C36_V48_ALP07/EDC16C36_V50_ALP07/EDC16C36_V54_ALP07/
EDC16C36_V58_ALP07EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 392 of 431
13B-392
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP7
CONTINUED
Check the high pressure circuit (external leaks) (see the end of ALP6 Fuel circuit external leaks)
Check the timing setting (and the position of the high pressure pump pinion)
Check the lower engine:
– Check the compressions using the CLIP diagnostic tool, use command VP036 Fuel supply inhibition.
– Only check the engine stand if there is noise or excessive vibration when idling.
If the checks are correct, contact the Techline.
A
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 393 of 431

13B-393
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP8 Oil leaks from the turbocharger
NOTESBefore analysing 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 fault of the turbocharger, 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 previously removed, refit it before starting the engine (risk of aspirating foreign bodies into 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?
YESNO
AB
EDC16C36_V44_ALP08/EDC16C36_V4C_ALP08/EDC16C36_V48_ALP08/EDC16C36_V50_ALP08/EDC16C36_V54_ALP08/
EDC16C36_V58_ALP08EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 394 of 431
13B-394
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP8
CONTINUED 1
Check the air compressor inlet or outlet
Check for a loose interface (inlet or outlet) that is the cause of
the air leak.
Note:
It is normal to find oil traces inside the pipes at the turbocharger
inlet or outlet, because the air entering the compressor was
laden with oil from the engine rebreathing circuit.
Is the suspected interface properly tightened?Tighten the interface or the pipe
concerned.
end of the procedure
Replace the pipe concerned (see MR 364 (Mégane II) or 370 (Scénic II), Mechanical systems, 12B,
turbocharging).
A
NO
YES
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 395 of 431
13B-395
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP8
CONTINUED 2
Is an oil leak present only at the casing of the compressor section?
The turbocharger is not faulty. The oil leak is from another
engine component and the oil is flowing onto the turbocharger.
Is an oil leak present at the turbocharger oil supply inlet or outlet?
Check the turbocharger oil supply inlet and outlet
Check for a loose interface (inlet or outlet) that is the cause of
the oil leak.
Is the suspected interface properly tightened?Tighten the pipe concerned.
end of the procedure
Replace only the seal or the pipe of the section concerned (see
MR 364 (Megane II) or 370 (Scenic II), Mechanical, 12B,
Turbocharging).
B
YES
NO
YES
NO
C
NO
YES
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 396 of 431
13B-396
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
V9 MR-372-J84-13B450$190.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP8
CONTINUED 3
Is an oil leak present at the interfaces of the turbine casing and the exhaust pipes?
End of procedure.
The turbocharger is not faulty. There is probably another fault in the engine.
Mark the component that is the source of the leak and refer to the repair manual (see MR 364 (Megane II) or 370
(Scenic II), 10A Engine and cylinder block assembly).
C
YES
NO
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58