Page 369 of 431

13B-369
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC011RAIL PRESSURE REGULATOR
NOTESPerform this fault finding procedure:
– following interpretation of an unresolved fault
– following an inconsistency recorded in the parameters,
– following a customer complaint (starting problems, engine speed instability, injection
noise).
Ignition on and engine stopped.
Use Wiring Diagram Technical Note, Mégane II ph2, Scénic II ph2.
Step 1
Check the continuity and absence of interference resistance on the following connections:
– Connection code 3HI between components 1105 and 120.
– Connection code 3FB between components 1105 and 983.
Run command AC011. If there is a slight whistling noise and clicking from the pressure regulator, go to step 2,
otherwise, check that the computer output stage is operating correctly:
Vehicle under + after ignition feed, clear the faults displayed by the diagnostic tool.
With the voltmeter in the direct current position:
With the pressure regulator connected, connect the voltmeter earth lead to connection 3HI of component 1105
and the positive lead to connection 3FB.
Run command AC011; the voltmeter should display four successive voltages of 2.2 V ± 0.2 V.
If the measurement is not correct, contact the Techline.
STEP 2
EDC16C36_V44_AC011/EDC16C36_V4C_AC011/EDC16C36_V48_AC011/EDC16C36_V50_AC011/EDC16C36_V54_AC011/
EDC16C36_V58_AC011EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 370 of 431

13B-370
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC011
CONTINUED
Step 2
In the event of rail overpressure:
Check that there are no air bubbles in the diesel fuel low pressure circuit.
Check that the rail pressure sensor is operating correctly.
Consult the interpretation of parameter PR038 Rail pressure.
If these checks reveal no irregularities, replace the regulator.
in the event of rail underpressure:
Check that the rail pressure sensor is operating correctly.
Consult the interpretation of parameter PR038 Rail pressure.
Check the low pressure diesel circuit priming.
Check the conformity of the diesel filter connections.
Check the condition of the filter (clogging and water saturation).
Check that there are no air bubbles between the filter and the high pressure pump.
Check the sealing of the low and high pressure diesel fuel systems: use ALP6 Fuel circuit leaks (visual
inspections, touch tests, odours, etc.) on:
pump body, pressure release valve, pipes, rail and injectors unions, injector wells, etc.
Check the conformity of the seal fitting on the pressure regulator.
Check the operation of the injectors, run Test 10 Poor injector operation.
Carry out the necessary repairs.
If the engine starts:
Clear any faults.
Check the pressure regulator by applying (see ALP7 Rough idle).
With the engine warm, leave it to idle for a few minutes (3 to 5 minutes):
– If it stalls and the fault reappears, replace the regulator.
– If it does not stall, stabilise the engine speed at 2000 rpm(1 minute) then accelerate at full load until it cuts out.
If the engine stalls, contact the Techline
If the engine does not startor there is no timing:
first, replace the regulator and if the fault is still present, contact the Techline.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 371 of 431

13B-371
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC012DAMPER VALVE
NOTESCarry out this interpretation:
– after DF226 Damper valve
– or after a customer complaint (starting faults, poor performance).
Ignition on and engine stopped.
Use Wiring Diagram Technical Note, Mégane II ph2, Scénic II ph2.
Check the continuity, insulation and absence of interference resistance on the following connections:
– Connection code 3VN,
– Connection code 3VM,
between components 1461 and 120.
Check for +12 V on connection 3FB of component 1461.
Check for earth on connectionNT of component1461.
If there is a repair method (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for
repair), repair the wiring, otherwise replace it.
With the vehicle ignition on, and the engine stopped:
Check that the damper valve is open.
If not, clean or replace the damper valve.
Actuate the valve using command AC012 and check the damper valve travel and the rest position of the valve.
Check the operation of the computer output stage with a voltmeter:
Actuate the valve with command AC012.
Positive lead to connection3FB and negative lead to connection3VN of component1461.
The voltmeter should display three cycles of ON-OFF (12.5 V then return to 0V).
If the measurement is correct, replace the damper valve.
If the measurement does not show any operation, contact the Techline.
EDC16C36_V44_AC012/EDC16C36_V4C_AC012/EDC16C36_V48_AC012/EDC16C36_V50_AC012/EDC16C36_V54_AC012/
EDC16C36_V58_AC012EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 372 of 431

13B-372
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC037PREHEATING RELAY
NOTESThis command is only run if fault DF025 Preheating unit diagnostic connection or
DF017 Preheating unit control circuit is present or stored and if no other fault is
present.
Ignition on and engine stopped.
Use Wiring Diagram Technical Note, Mégane II ph2, Scénic II ph2.
Before applying the following fault finding procedure, check that the battery voltage is not below 12 V.
Otherwise, recharge the battery.
Check the connections on the preheating unit, heater plugs and injection computer.
If there is a repair method (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for
repair), repair the wiring, otherwise replace it.
Measure the resistance of the heater plugs. If this resistance is > 2 Ω, replace the defective plug(s).
Check the continuity and the absence of interference resistance on the following connections:
– Connection code 37AA between components257 and 681.
– Connection code 37AB between components 257 and 682.
– Connection code 37AC between components 257 and 683.
– Connection code 37AZ between components 257 and 680.
Check the condition of fuse FM12 (70 A) of the preheating unit supply. Replace it if necessary.
Then check for +12 V on connection BP35 of component 257.
Check the continuity, insulation, and the absence of interference resistance of the following connections:
– Connection code 3FF,
– Connection code 3FY,
Between components 257 and 120.
If the fault is still present, replace the pre-postheating unit.
EDC16C36_V44_AC037/EDC16C36_V4C_AC037/EDC16C36_V48_AC037/EDC16C36_V50_AC037/EDC16C36_V54_AC037/
EDC16C36_V58_AC037EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 373 of 431

13B-373
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC038LOW-SPEED FAN ASSEMBLY RELAY
NOTESThere must be no present or stored faults.
Perform this fault finding after an engine cooling fault or air conditioning fault.
Refer to the Wiring Diagram Technical Notes for the vehicle to locate the fuses and
relays concerned.
Ignition on and engine stopped.
Use Wiring Diagram Technical Note, Mégane II ph2, Scénic II ph2.
If the low speed fan assembly relay does not operate when command AC038 is run:
Check the low-speed fan assembly relay mounting and the connections of the engine management computer.
Check the fan assembly connections.
If there is a repair method (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for
repair), repair the wiring, otherwise replace it.
If the fault is still present, check that the relay is actuated by the engine management computer as follows:
Disconnect the low-speed fan assembly relay, and fit a 50 to 100 Ω resistor on the relay mounting in place of the
coil, and connect a voltmeter as follows:
– positive terminal to +12 V battery,
– negative terminal to connection 3JN of component 336.
Run command AC038
If the voltmeter shows the battery voltage (4 ON-OFF cycles of 10 seconds), replace the relay.
If the low speed fan assembly relay is supplied using command AC038, but there is still a fan assembly activation
fault, check using the wiring diagram.
The conformity of the fan assembly FM15 maxi-fuse.
EDC16C36_V44_AC038/EDC16C36_V4C_AC038/EDC16C36_V48_AC038/EDC16C36_V50_AC038/EDC16C36_V54_AC038/
EDC16C36_V58_AC038EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 374 of 431

13B-374
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC038
CONTINUED
–Check for +12 V on connection 49B of component 262 and on connection BP71 of component 188.
– Check for earth on connectionMAS of component262.
If the tests are ok, replace the defective fan.
If not, carry out the following operations:
Check the continuity, insulation and the absence of interference resistance on the following connections:
– Connection code 49B between components 262 and 336.
– Connection code MAS between components 262 and MAS.
– Connection code 49A between components 188 and 337.
– Connection code BP71 between components 188 and 597.
– Connection code 49T between components 336 and 337.
– Connection code 3FB
– Connection code 3JN,
between components 336 and 120.
If there is a repair method (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for
repair), repair the wiring, otherwise replace it.
– Check the conformity of the fan assembly.
Carry out the necessary repairs.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 375 of 431

13B-375
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC039HIGH SPEED FAN ASSEMBLY
NOTESThere must be no present or stored faults:
Perform this fault finding after an engine cooling fault.
Refer to the Wiring Diagram Technical Notes for the vehicle to locate the fuses and
relays concerned.
Ignition on and engine stopped.
Use Wiring Diagram Technical Note, Mégane II ph2, Scénic II ph2.
If, when running command AC039, the high-speed fan assembly relay is not activated:
Check the high-speed fan assembly relay mounting and the connections of the engine management computer.
Check the fan assembly connections.
Repair if necessary.
If the fault is still present, check that the relay is actuated by the engine management computer as follows:
Disconnect the high speed fan assembly relay 335, fit a 50 to 100 Ω resistor on its mounting in place of the coil,
and connect a voltmeter as follows:
- positive terminal to +12 V battery,
- negative terminal to connection 3JP of component 335.
Run command AC039.
If the voltmeter shows the battery voltage (4 ON-OFF cycles of 10 seconds), replace the relay.
Disconnect the high speed fan assembly relay 337, fit a 50 to 100 Ω resistor on its mounting in place of the coil,
and connect a voltmeter as follows:
- positive terminal to +12 V battery,
- negative terminal to connection 3JP of component 337.
Run command AC039.
If the voltmeter shows the battery voltage (4 ON-OFF cycles of 10 seconds), replace the relay.
If the high-speed fan assembly relays are fed using command AC153, but there is still a fan activation fault, check
using the wiring diagram:
The conformity of the fan assembly FM15 maxi-fuse.
EDC16C36_V44_AC039/EDC16C36_V4C_AC039/EDC16C36_V48_AC039/EDC16C36_V50_AC039/EDC16C36_V54_AC039/
EDC16C36_V58_AC039EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58
Page 376 of 431

13B-376
AFTER REPAIRRepeat the conformity check in the interpretation of statuses and parameters
V9 MR-372-J84-13B450$170.mif
DIESEL INJECTION
Fault finding – Interpretation of commands13B
AC039
CONTINUED
–Check for +12 V on connection BP71 of component 188 and on connection 49B of component 262.
–Check for earth on connection 49A of component 188 and on connection MAS of component 262.
If the tests are ok, replace the defective fan.
If not, carry out the following operations:
Check the continuity, insulation and the absence of interference resistance on the following connections:
– Connection code 49B between components 262 and 335.
– Connection code MAS between components 262 and MAS.
– Connection code 49A between components 188 and 337.
– Connection code BP71 between components 188 and 597.
– Connection code BP71 between components 335 and 597.
– Connection code 3FB,
– Connection code 3JP,
between components 335 and 120.
– Connection code MAS between components 337 and MAS.
– Connection code 3FB,
– Connection code 3JP,
between components 337 and 120.
If there is a repair method (see Technical Note 6015A, Repairing electrical wiring, Wiring: Precautions for
repair), repair the wiring, otherwise replace it.
EDC16 C36
Program No.: 91
Vdiag No.: 44, 4C, 48,
50, 54, 58