Page 156 of 198

13B-156V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 8
CONTINUED 1
At the end of both cycles, the return volume of each injector should be 35 ml maximum.
If the return volume of one of the injectors is greater than 35 ml, replace the faulty injector (see MR 364 (Mégane
II), MR 370 (Scénic II), Mechanical, 13B, Diesel injection, Diesel injector: Removal - Refitting).
Disconnect the 4 transparent pipes and reconnect the injector return circuit.
Carry out the following test to confirm the repair:
–With the ignition off, disconnect the low pressure actuator from the pump (brown IMV connector) and connect
the test adapter (test IMV, Mot. 1711),
– electrically disconnect the 4 injectors,
– switch on the ignition, connect the diagnostic tool and re-establish dialogue with the injection system,
– Go to the Main computer statuses and parameters screen,
– engage the starter for 5 seconds,
– read the rail pressure maximum value (PR038) on the diagnostic tool during the test.
If the rail pressure (PR038) is less than 1050 bar, run test 6 High pressure system check.
– Switch off the ignition, and reconnect the four injectors electrically,
– disconnect the test filling actuator (test IMV) and reconnect the low pressure actuator connector (IMV) to the
pump
Switch the ignition back on, and clear the injection faults using the diagnostic tool
If the rail pressure (PR038 Rail pressure) is greater than 1050 bar, the repair is correct
End of TEST 8.
Page 158 of 198

13B-158V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 8
CONTINUED 3
Carry out the following test to confirm the repair:
–With the ignition off, disconnect the low pressure actuator from the pump (brown IMV connector) and connect
the test adapter (test IMV, Mot. 1711),
– electrically disconnect the four injectors,
– switch on the ignition, connect the diagnostic tool and re-establish dialogue with the injection system,
– go to the Main computer statuses and parameters screen,
– engage the starter for 5 seconds,
– read the rail pressure maximum value (PR038) during the test on the diagnostic tool.
If the rail pressure (PR038) is less than 1050 bar, run test 6 High pressure system check.
– Switch off the ignition, and reconnect the four injectors electrically,
– disconnect the test IMV and reconnect the low-pressure actuator connector to the pump,
– switch on the ignition again, and clear the injection faults using the diagnostic tool.
If the rail pressure (PR038 Rail pressure) is greater than 1050 bar, the repair is correct
End of TEST 8.
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 162 of 198

13B-162V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 13 Diesel fuel conformity check
WARNING
– During this operation, it is essential to:
– refrain from smoking or bringing incandescent objects close to the work area,
– guard against petrol splashes caused by the residual pressure in the pipes,
– wear safety goggles with side guards,
– wear leaktight gloves (Nitrile type).
IMPORTANT
– To avoid any corrosion or damage, protect the areas on which fuel is likely to run.
– To prevent impurities from entering the circuit, place protective plugs on all fuel circuit components
exposed to the open air.
Preparations:
Weigh an empty 1300 ml plastic cup (part no. 77 11 171 413) with its cover (part no. 77 11 171 416) using
electronic scales such as those used in body paint workshops (for example: PANDA, part no. 77 11 224 995).
Record the weight of the empty plastic cup.
This type of plastic cup is used to prepare paint.
Take a 1 litre fuel sample from the diesel filter outlet (see MR 364 (Mégane II) or 370 (Scénic II), Mechanical,
19C, Tank, Fuel tank: Draining), using a pneumatic transfer pump (part no. 634-200) and place it in the 1300 ml
plastic cup.
Cover the plastic cup with its cover and let it settle for approximately2 minutes.
Is the fuel cloudy or does it
separate into two parts?Presence of water in diesel fuel, the fuel is not compliant.
Drain the fuel circuit, including the tank (see MR 364 (Mégane) or
370 (Scénic), Mechanical, 19C, Tank, Fuel Tank: Draining).
YES
A
NO
DDCR_V44_TEST13/DDCR_V48_TEST13
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 168 of 198

13B-168
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 1
Does the starter motor operate correctly (minimum
engine speed = 200 rpm)?Carry out the necessary repairs
Is the compression in order? 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
Is PR038 Rail pressure less than 50 bar under +
after ignition feed?Apply the fault finding procedure for DF007
Rail pressure sensor circuit
Check the low pressure circuit by running TEST 1 Low pressure circuit check.
Check the injectors by running TEST 3 Injector check.
Visually check that there are no leaks on the high pressure circuit by running TEST 7 High pressure circuit
sealing check.
A
NO
YES
NO
YES
YES
NO
A