Page 145 of 198
13B-145V4 MR-372-J84-13B000$110.mif
DIESEL INJECTION
Fault finding – Interpretation of parameters13B
DDCR INJECTION
Vdiag No.: 44, 48
PR064 COOLANT TEMPERATURE
NOTESNone.
Check the condition of the coolant temperature sensor connections.
If necessary replace the sensor.
Measure the resistance between tracks 2 and 3 of the coolant temperature sensor.
Theoretical values:
12.46 kΩ ± 1128 Ω at -10°C.
2252 Ω ± 112.6 Ω at 25°C.
811.4 Ω ± 38.4 Ω at 50°C.
282.6 Ω ± 7.83 Ω at 80°C.
Replace the coolant temperature sensor if it is not correct.
DDCR_V44_PR064/DDCR_V48_PR064
AFTER REPAIRDeal with any faults declared by the diagnostic tool. Clear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
Page 146 of 198

13B-146V4 MR-372-J84-13B000$110.mif
DIESEL INJECTION
Fault finding – Interpretation of parameters13B
DDCR INJECTION
Vdiag No.: 44, 48
CLEARING
RZ001: fault memory.
This command is used to clear stored faults from the computer's memory.
RZ002: EGR adaptives.
Run this command only when replacing the EGR valve.
RZ004: Pressure regulation parameters.
Run this command when replacing all 4 injectors at once. It enables you to reset the injector adaptive programs.
RZ005: Programming.
This command lets you reinitialise the entire computer configuration according to the vehicle.
COMMANDS
LPG - FUEL CIRCUIT tab
AC010: High-pressure pump.
This command lets you listen for the operation of the high pressure pump.
AC005 to AC008: Injectors of cylinders 1 to 4.
These commands let you listen for the injector on the selected cylinder.
AC028: Static test.
This command activates fault finding for the EGR and high pressure pump circuits.
AC029: High-pressure circuit seal check.
This command lets you check the high pressure circuit sealing after a procedure has been carried out.
AC212: New pump chamber filling.
Use this command only after replacing the high pressure pump (see High pressure pump replacement in
Replacement of components). This command is used to activate the pump repriming sequence.
IGNITION - PREHEATING tab
AC001: Preheating unit.
This command actuates the preheating unit to test the heater plug supply.
EMISSION CONTROL - OBD tab
AC002: EGR solenoid valve.
This command lets you listen to the mechanical operation of the EGR valve.
AC028: Static test.
This command activates fault finding for the EGR and high pressure pump circuits.
TURBO - INLET AIR CIRCUIT tab
AC004: Turbocharging solenoid valve.
This command lets you listen for the operation of the turbocharging solenoid valve.
Page 147 of 198
13B-147V4 MR-372-J84-13B000$120.mif
13B
DDCR INJECTION
Vdiag No.: 44, 48
*Technical Note 3419: Fault finding on the turbocharger for petrol and diesel engines
NOTESOnly consult these tests when dealing with a fault finding chart (ALP) or when
interpreting faults.
Low pressure circuit check TEST 1
Electrical circuit checkTEST 2
Injector checkTEST 3
Inlet circuit checkTEST 5
High pressure system check TEST 6
High pressure circuit sealing check TEST 7
Injector return flowTEST 8
Diesel filter checkTEST 9
Turbocharger solenoid valve checkTEST 10: Apply
TEST 4 of
Technical Note
3419*
Turbocharger air chainTEST 11
TurbochargerTEST 12: Apply
TEST 7 of
Technical Note
3419*
Diesel fuel conformity check TEST 13
DIESEL INJECTION
Fault finding – Tests
Page 148 of 198
13B-148V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 1 Low pressure circuit check
Check the conformity of the low pressure circuit
connections
Are the low pressure circuit connections correct? Carry out the necessary repairs.
Check the condition of the priming bulb, and that it is
working properly.
Look for leaks at the unions.
Are there leaks from the hoses and unions? Carry out the necessary repairs
Check that there are no air bubbles in the diesel fuel. Bleed the low-pressure circuit.
Place a container under the filter.
Disconnect the return hose from the filter and
plug the filter.
Pump using the priming bulb until there is no air
left.
Reconnect the return hose immediately. Are air bubbles present in the low pressure circuit?
Low pressure circuit correct.
NO
YES
YES
NO
YES
NO
DDCR_V44_TEST01/DDCR_V48_TEST01
Page 149 of 198
13B-149V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 2 Electrical circuit check
Check the battery charge and that the alternator is
operating correctly (see 87G, Engine compartment
connection unit for Mégane II or Scénic II).
Is the charging circuit in good order? Carry out the necessary repairs
Check the fuses.
Are the fuses correct? Carry out the necessary repairs
Check that the injection locking relay is operating
correctly.
Is the injection locking relay working properly? Carry out the necessary repairs
Check the engine earths.
Are the engine earths correct?Carry out the necessary repairs
The electrical circuit is in good order.
NO
YES
NO
YES
NO
YES
NO
YES
DDCR_V44_TEST02/DDCR_V48_TEST02
Page 150 of 198
13B-150V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 3 Injector check
Is diesel fuel present around the injectors?Locate the source of the leak and carry out the
necessary repairs.
Control the injectors with the commands
AC005 Cylinder 1 injector,
AC006 Cylinder 2 injector,
AC007 Cylinder 3 injector,
AC008 Cylinder 4 injector.Check the insulation and the continuity of the
electrical circuit.
Run test 9 Diesel filter check.
If test 9 is correct, replace the faulty injectors (MR 364
(Mégane II) or MR 370 (Scénic II), Mechanical, 13B,
Diesel injection, Diesel injector: Removal -
Refitting). Can you hear the valve moving when you are
1metre away from the vehicle?
End of TEST 3.YES
NO
NO
YES
DDCR_V44_TEST03/DDCR_V48_TEST03
Page 151 of 198
13B-151V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
TEST 5 Inlet circuit check
Check for air leaking in or out.
Is air leaking in or out? Carry out the necessary repairs
Check the condition of the air filter. Replace the air filter (see MR 364 (Mégane II) or
MR 370 (Scénic II), Mechanical, 12A, Fuel
mixture, Air filter, Removal - Refitting). Is the air filter in order?
Check that the inlet manifold is not obstructed
(clogged).
Is the inlet manifold blocked? Clean the inlet manifold.
Air system in good order.
YES
NO
NO
YES
YES
NO
DDCR_V44_TEST05/DDCR_V48_TEST05
Page 152 of 198

13B-152V4 MR-372-J84-13B000$120.mif
DIESEL INJECTION
Fault finding – Tests13B
DDCR INJECTION
Vdiag No.: 44, 48
IMV = fuel flow actuator
TEST 6 High pressure system check
NOTESSpecial note:
Certain faults make it impossible to carry out this test - deal with these first.
IMPORTANT: It is pointless and dangerous to engage the starter motor for more
than 5 seconds.
Preliminary Checks:
– Check for the presence of fuel
– Check that there is no air in the low pressure circuit. Run TEST 1: Low pressure circuit check.
– Ensure that the correct fuel is being used. Run TEST 13 Diesel fuel conformity check.
It is possible to check the high pressure supply pump capacity by carrying out the following procedure:
–With the ignition off, disconnect the low pressure actuator from the pump (IMV brown connector) and connect
a test IMV or the MOT. 1711 adapter.
– 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.
– Run the test cold, PR064 Coolant temperature < 30°C or equal to the ambient temperature.
– Engage the starter for 5 seconds.
– Read the rail pressure maximum value (PR038) during the test on the diagnostic tool.
Is the rail pressure greater than 1050 bar?
A
NO
B
YES
DDCR_V44_TEST06/DDCR_V48_TEST06