Page 160 of 198

13B-160V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 11 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, 12B, Turbocharging).
YESNO
YES
NO
YES
A
NO
DDCR_V44_TEST11/DDCR_V48_TEST11
Page 161 of 198

13B-161V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 11
CONTINUED
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:
– the compressor outlet pipe to the turbocharging air cooler (the
turbocharging air cooler does not exist for all engines),
– 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? Replace the defective parts (see
MR 364 (Mégane II) or 370 (Scénic
II), Mechanical, 12B,
Turbocharging).
Run TEST 10: Turbocharger control solenoid valve check.
A
NO
YES
NO
YES
NO
Page 166 of 198

13B-166
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
13B
InjectionDDCR
Vdiag No.: 44, 48
ALP1 No dialogue with the computer
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
To check that the diagnostic tool is not causing the fault, try to establish dialogue with a computer on another
vehicle. If the diagnostic tool is not the cause and communication cannot be established with any other computer
on the same vehicle, it is possible that another computer is disrupting the multiplex network. Check the battery
voltage and make the necessary adjustments to obtain a correct voltage (9.5 V < Battery voltage < 17.5 V).
Carry out fault finding on the multiplex network using the diagnostic tool (see 88B, Multiplexing).
Check the presence and the condition of the injection fuses on the UPC and on the engine fuse box.
Check the connection of the computer connectors and the condition of its connections.
Check the injection computer earths (quality, oxidation, tightness of earth bolts on the battery terminal).
Check that the supply to the computer is correct:
–AP15 between components 1337 and 120,
–NH between earth and component 120,
–3FB1 between components 1337 and 120,
–3FB2 between components 1337 and 120.
Ensure that the supply to the diagnostic socket is correct:
–BP32 between components 225 and 260,
–AP43 between components 225 and 1337,
–MN between earth and component 225,
If dialogue has still not been established after these checks, contact the techline.
DDCR_V44_ALP01/DDCR_V48_ALP01
DIESEL INJECTION
Fault finding – Fault finding charts
Page 167 of 198

13B-167
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
InjectionDDCR
Vdiag No.: 44, 48
ALP2 The engine will not start
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Check that the fuel tank is correctly filled and that the fuel is correct: run TEST 13 Diesel fuel conformity check.
Check the levels of engine oil and coolant.
Check the air inlet circuit by running TEST 5 Inlet circuit check.
Is the catalytic converter clogged or damaged?Replace the catalytic converter (see MR
364 (Mégane II) or MR 370 (Scénic II),
Mechanical, 19B, Exhaust, Catalytic
converter: Removal - Refitting).
Check the air inlet circuit by running TEST 2 Electrical circuit check.
Check the electrical conformity of the heater plugs (the resistance value of the heater plug must be less than 2 Ω).
Is the timing set correctly? Carry out the necessary repairs.
Visually check the condition of the engine wiring harness.
YES
NO
NO
YES
A
DDCR_V44_ALP02/DDCR_V48_ALP02
Page 169 of 198
13B-169
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
InjectionDDCR
Vdiag No.: 44, 48
ALP2
CONTINUED 2
Check the high pressure system by running TEST 6 High pressure system check.
Check that the computer connectors are properly locked.
Check the condition of the computer connections (bent pin, signs of corrosion, silicone, etc.).
If the connector(s) are faulty and if there is a repair procedure (see Technical Note 6015A, Repairing electrical
wiring, Wiring: Precautions for repair), repair the connector, otherwise replace the wiring.
Contact the Techline if the customer complaint is still present.
A
Page 171 of 198

13B-171
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
InjectionDDCR
Vdiag No.: 44, 48
ALP3
CONTINUED
Visually check the condition of the engine wiring harness.
Check the air inlet circuit by running TEST 2 Electrical circuit check.
Using the diagnostic tool, check that the injector codes (C2I) are correctly entered on the identification screen. If
not, configure the correct injector codes using command SC002 Enter injector codes.
Check the low pressure circuit by running TEST 1 Low pressure circuit check.
Visually check that there are no leaks on the high pressure circuit by running TEST 7 High pressure circuit
sealing check.
Check the high pressure system by running TEST 6 High pressure system check.
Check that the computer connectors are properly locked.
Check the condition of the computer connections (bent pin, signs of corrosion, silicone, etc.).
If the connector(s) are faulty and if there is a repair procedure (see Technical Note 6015A, Repairing electrical
wiring, Wiring: Precautions for repair), repair the connector, otherwise replace the wiring.
Contact the Techline if the customer complaint is still present.
A
YES
Page 172 of 198

13B-172
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
InjectionDDCR
Vdiag No.: 44, 48
ALP4 Starting difficult with warm engine
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Check that the fuel tank is correctly filled and that the fuel is correct by running TEST 13 Diesel fuel conformity
check.
Check the air inlet circuit by running TEST 5 Inlet circuit check.
Is the compression in order? Carry out the necessary repairs.
Is the timing set correctly? Carry out the necessary repairs.
Using the diagnostic tool, check that the injector codes (C2I) are correctly entered on the identification screen. If
not, configure the correct injector codes using command SC002 Enter injector codes.
Visually check the condition of the engine wiring harness.
Check the low pressure circuit by running TEST 1 Low pressure circuit check.
NO
YES
NO
YES
A
DDCR_V44_ALP04/DDCR_V48_ALP04
Page 173 of 198

13B-173
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V4 MR-372-J84-13B000$140.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
InjectionDDCR
Vdiag No.: 44, 48
ALP4
CONTINUED
Control the injectors using the commands:
– AC005 Cylinder 1 injector,
– AC006 Cylinder 2 injector,
– AC007 Cylinder 3 injector,
– AC008 Cylinder 4 injector.
Can you hear the valve moving when you are
1 metre from the vehicle?Run Test 9 Diesel filter check.
If test 9 is correct, replace only the faulty
injectors (see MR 364 (Mégane II) or MR 370
(Scénic II), Mechanical, 13B, Diesel
injection, Diesel injector: Removal -
Refitting).
Check the high pressure system by running TEST 6 High pressure system check.
Check that the computer connectors are properly locked.
Check the condition of the computer connections (bent pin, signs of corrosion, silicone, etc.).
If the connector(s) are faulty and if there is a repair procedure (see Technical Note 6015A, Repairing electrical
wiring, Wiring: Precautions for repair), repair the connector, otherwise replace the wiring.
Contact the Techline if the customer complaint is still present.
A
NO
YES