Page 153 of 198

13B-153V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 6
CONTINUED
– Switch off the ignition, reconnect the electrical
connections to the four injectors and the low-
pressure actuator.
– Switch on the ignition again, and clear the
injection faults using the diagnostic tool.
– Check if there is no fuel leak in the high pressure
circuit. Run TEST 7 High pressure circuit
sealing check
– Check the conformity of the diesel filter. Run
TEST 9 Diesel filter check.
– Carry out fault finding on the injectors by
checking the return flow volume of the four
injectors, run TEST 8 Injector return flow.
–Is TEST 8 OK?The pump can supply the operating pressure.
Switch off the ignition, reconnect the electrical
connections
to the four injectors and the low pressure actuator.
Switch on the ignition again, and clear the injection
faults using the diagnostic tool.
Check if there is no fuel leak in the high pressure
circuit. Run TEST 7 High pressure circuit sealing
check.
Carry out fault finding on the injectors by checking the
return flow volume of the four injectors, run TEST 8
Injector return flow.
If TEST 8 is correct, the high pressure fuel circuit is
correct.
Replace the faulty injectors
(see MR 364 (Mégane II) or
MR 370 (Scénic II),
Mechanical, 13B, Diesel
injection, Diesel injector:
Removal - Refitting)Replace the high pressure pump (see MR 364 (Mégane II) or MR 370
(Scénic II), Mechanical, 13B, Diesel injection, High pressure pump:
Removal - Refitting).
A
NO
B
YES
NOYES
Page 155 of 198

13B-155V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 8 Injector return flow
NOTESSpecial note:
Certain faults make it impossible to carry out this test - deal with these first.
Does the engine start?
Command AC029 also checks the return volume of each injector to detect an internal injector leak.
Be careful with any objects (tool or other) on the engine housing during the four cycles of the operation
(possible vibrations).
Tooling required
–Mot. 1711 Injector flow measuring kit.
Or: Use four pipes with internal diameter 4mm and approximately 50 cm in length, and four graduated measuring
cylinders.
Procedure
– Ensure that the engine coolant temperature is above 60°C,
– switch off the ignition,
– disconnect the return pipes from the four injectors,
– cap the pump venturi tube to prevent the low-pressure circuit from depriming,
– connect the four transparent tubes in place of the return pipes,
– put the other ends of the four pipes into four graduated measuring cylinders.
– After finishing these preparations, start the engine and let it idle for 2 minutes.
Note: This idle time must be respected for the test results to be interpreted correctly.
–Run command AC029 High pressure circuit sealing check
.The engine will automatically carry out a cycle of four accelerations to increase the rail pressure and measure the
internal injector leaks under these conditions.
–Once the cycle is complete, run command AC029 again to obtain a correct reading of the return volume of
each injector.
– Switch off the engine at the end of the cycle.
NOA
YES
DDCR_V44_TEST08/DDCR_V48_TEST08
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 157 of 198

13B-157V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 8
CONTINUED 2
If the engine does not start, only the static leak can be measured, that is the leak with the injector closed, not being
actuated and under high pressure.
Make sure that the ignition circuit is working correctly (minimum engine speed 200 rpm).
Tooling required
– Mot. 1711 Injector flow measuring kit.
Or: Use four tubes of internal diameter 4 mm and approximately 50 cm long and a test adapter (TEST IMV).
Procedure
– Switch off the ignition,
– disconnect the return pipes from the four injectors,
– cap the pump venturi tube to prevent the low-pressure circuit from depriming,
– connect the four transparent pipes in place of the return pipes (Mot. 1711),
– disconnect the low pressure actuator from the pump (brown IMV connector) and connect a test IMV or the
adapter of Mot. 1711,
– electrically disconnect the four injectors,
– switch on the ignition and engage the starter for 5 seconds,
– measure the amount of diesel fuel in each pipe.
Replace the injectors that have a leak return greater than 10 cm.
Switch off the ignition, and reconnect the four injectors electrically.
Disconnect the test IMV and reconnect the low-pressure actuator connector to the pump. Disconnect the
four transparent tubes and reconnect the injectors return circuit. Switch on the ignition again, and clear the injection
faults using the diagnostic tool.
A
NO
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 159 of 198

13B-159V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 9 Diesel filter check
Check the conformity of the diesel filter. Replace the filter with an original part (see MR
364 (Mégane II) or MR 370 (Scénic II),
Mechanical, 13A, Fuel supply, Fuel filter:
Removal - Refitting) Is the diesel filter in order?
– Switch off the ignition and analyse the diesel fuel in the diesel filter.
– Disconnect the diesel supply and return hoses from the filter.
– Block the filter inlets and outlets straight away with appropriate plugs.
– Remove the filter from its holder and shake it firmly while holding the caps in place. Tap the edge of the filter
with a screwdriver handle to detach any contamination. Empty the contents of the filter into a glass container by
lifting a protective plug, then loosening and completely removing the bleed screw.
Is there a deposit of black particles at the bottom of the container?
Pass a magnet beneath the container to collect
all the metal particles. Take the magnet away
from the container.Diesel filter in good order.
Do the particles collected, using the magnet,
cover a surface area greater than 1 cm
2?
Replace the entire injection system Diesel filter in good order.
NO
YES
YESNO
YES
YES
DDCR_V44_TEST09/DDCR_V48_TEST09
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