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 406 of 431

13B-406V9 MR-372-J84-13B450$200.mif
DIESEL INJECTION
Fault finding – Tests13B
TEST2 Turbocharger air chain
Check for the air filter
Check the replacement interval of the air filter on 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?
Check the condition of the air filter
Visually inspect the condition of the filtering section of the air
filter.
Is either the air filter or its seal damaged?
Is the air filter fouled (does it contain a lot of impurities)?Replace the air filter (see MR 364
(Mégane II) or 370 (Scénic II),
Mechanical, 12A, Fuel mixture, Air
filter, Removal - Refitting).
Low pressure circuit check
Note:
Depending on the vehicle type, the best visual access will be
either from above or from below.
Visually inspect the condition of the following components:
– fresh air inlet scoop on the front panel of the vehicle,
– air inlet pipe to the air filter,
– air pipe of the filter until the compressor inlet,
– mountings of the air flowmeter.
Is one of these components incorrect (disconnected,
cut, bent, pierced or kinked pipes)?Replace the defective parts (see MR
364 (Mégane II) or 370 (Scénic II),
Mechanical systems, 12B,
Turbocharging).
YESNO
YES
NO
YES
NO
A
EDC16C36_V44_TEST2/EDC16C36_V4C_TEST2/EDC16C36_V48_TEST2/EDC16C36_V50_TEST2//EDC16C36_V54_TEST2/
EDC16C36_V58_TEST2
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 407 of 431

13B-407V9 MR-372-J84-13B450$200.mif
DIESEL INJECTION
Fault finding – Tests13B
TEST2
CONTINUED 1
High pressure circuit check
Note:
Depending on the vehicle type, the best visual access will be either from
above or from below.
Visually inspect the condition of the following components:
– outlet pipe of the compressor to the turbocharging air cooler,
– outlet pipe of the turbocharging air cooler to the inlet manifold,
– inlet manifold,
– temperature and pressure sensors.
Is one of these components incorrect (disconnected, cut, bent,
pierced or kinked pipes)?
Replace the defective parts
(see MR 364 (Mégane II) or
370 (Scénic II),
Mechanical, 12B,
Turbocharging). Exhaust system check
Visually inspect the condition of the following engine sections:
– from the exhaust manifold circuit to the turbocharger turbine,
– from the turbine outlet pipe to the end of the exhaust pipe,
– from the inlet manifold to the EGR valve
– check that the temperature and pressure sensors are connected.
Do some of these components have black or white marks on them?
Run test 6: Turbocharger control solenoid valve test.
A
YES
NO
YES
NO
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 410 of 431

13B-410V9 MR-372-J84-13B450$200.mif
DIESEL INJECTION
Fault finding – Tests13B
TEST4 Checking the turbocharged air inlet circuit
Engine stopped:
Check the sealing of the low and high pressure air circuits (air leaks in or out, upstream/downstream of the
turbocharger).
Check the parts that are abnormally greasy of the circuit and reveal a lack of tightness.
Check:
– The condition and fitting of the ducts (foreign bodies, clogged, displaced, kinked, broken, pierced, cut, tightness
of the mounting bolts, etc.).
– the presence, condition and fitting of the seals,
– the presence and tightening of the clamps,
– the fitting of the turbocharger pressure sensor.
– the pipe and take-off point between the air duct and the turbocharging sensor
Carry out the necessary repairs
Checking the air filter.
Check:
– that the air filter unit inlet and outlet are not blocked,
– the condition and the assembly of the air filter unit (disconnected, broken, pierced, etc.),
– the cleanliness, conformity and the non-distortion of the filter element,
– The air flowmeter: run test 5: Air flowmeter.
Carry out the necessary repairs.
A
EDC16C36_V44_TEST4/EDC16C36_V4C_TEST4/EDC16C36_V48_TEST4/EDC16C36_V50_TEST4/EDC16C36_V54_TEST4/
EDC16C36_V58_TEST4
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 411 of 431

13B-411V9 MR-372-J84-13B450$200.mif
DIESEL INJECTION
Fault finding – Tests13B
TEST4
CONTINUED
Check:
– the condition of the damper valve,
– the tightening of the mounting bolts,
– cracks in the damper valve.
Carry out the necessary repairs.
Replace if necessary.
Check that there is no leak at the exhaust manifold, in particular at the exhaust manifold/turbocharger connection.
Check the exhaust system: run test 1 Exhaust pipe check in ALP2.
Carry out the necessary repairs.
Carry out a visual inspection of the EGR circuit sealing.
Note: the operating play in the EGR heat exchanger valve shaft produces small black marks due to a slight leak
of no importance. Do not replace this part.
Replace if necessary.
Check the condition of the intercooler:
– clogging,
– leaks (vehicle stationary, stabilise the engine speed between 3500 rpm and 4000 rpm and check that there are
no leaks).
Replace if necessary.
Check that the take-off point for the turbocharging pressure sensor is not blocked.
Replace if necessary.
END OF TEST.
A
AFTER REPAIRCarry out a road test followed by a complete check with the diagnostic tool.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58