
13B-478
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP4
CONTINUED 2
Perform the following road test (looking for a loss of power when accelerating under full load):
– in the highest gear ratio, accelerate fully,
– lift your foot off the accelerator pedal completely for at least 2 seconds,
– accelerate fully again,
– release the accelerator pedal completely,
– accelerate slightly.
If the loss of power was not noted during slight acceleration and if there was a loss of engine power during each
acceleration at full load, replace the diesel fuel injector return rail and its overpressure valve (see MR364
(Mégane II ph2), MR370 (Scénic II ph2), MR 395 (Laguna II ph2), 402 (Vel Satis ph2), 405 (Espace IV ph2)
Mechanical, 13B, Diesel injection, Diesel injector fuel return rail: Removal - Refitting).
Check the connection and positioning of the differential pressure sensor (see MR 395 (Laguna II ph2), 402 (Vel
Satis Ph2), 405 (Espace IV ph2), 364 (Mégane II ph2), 370 (Scénic II ph2) Mechanical, 19B, Exhaust, Particle
filter pressure sensor: Removal - Refitting).
Check the conformity of the accelerator pedal position sensor, the brake pedal sensor, the atmospheric pressure
sensor, the exhaust gas recirculation valve, and the damper valve (see Interpretation of statuses and
parameters).
Check the consistency of the signal from the air flowmeter, the engine coolant temperature sensor, the fuel
temperature sensor and the engine speed sensor.
Check the connections, the continuity and the absence of interference resistance of the following components:
– the air flowmeter (apply DF056 Air flow sensor circuit)
– the engine coolant temperature sensor (apply DF001 Coolant temperature sensor circuit)
– the fuel temperature sensor (apply DF098 Fuel temperature sensor circuit)
– the engine speed sensor (apply DF195 Engine speed/camshaft sensor consistency).
A
YES
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-479
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP4
CONTINUED 3
Check:
– That the diesel filter is not clogged.
– That there are no leaks on the high and low pressure diesel circuits: run Test 3 Low pressure circuit check.
–Test the high pressure fuel circuit:
Run scenario SC035 High pressure fuel circuit fault finding (see Interpretation of commands).
Continue by checking the following:
– The connection of the oil vapour rebreathing circuit.
– The pump pressure regulator (MPROP), (jamming - sticking); apply the interpretation of command AC226 Pump
pressure regulator.
– The rail pressure regulator (DRV), (jamming - sticking); apply the interpretation of command AC225 Rail
pressure regulator.
– Check the engine timing (and the position of the high pressure pump sprocket).
– Check the engine compressions: use a compression gauge, M9R hose end piece, part no. Mot. 1772 and apply
command VP036 Fuel supply inhibition (see Interpretation of commands).
If the fault is still present, contact the techline.
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-480
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP5 Irregular engine operation
NOTESBefore analysing this customer complaint, check that there are no faults, and the
conformity (or otherwise) of the parameters and statuses, using the diagnostic tool.
If the customer complaint is not eliminated, perform the following checks.
Use the Wiring Diagram Technical Note, Laguna II ph2, Vel Satis ph2, Espace IV
ph2, Mégane II ph2, Scénic II ph2.
If the engine races during gear changes, if there is a floor mat, check that this is not blocking the accelerator pedal,
the brake pedal and the clutch pedal, then check the conformity of the clutch switch and the conformity of the
accelerator pedal sensor when the pedal is released (see PR086 Pedal potentiometer voltage gang 1 and
PR088 Pedal potentiometer voltage gang 2, Sensor supply).
Measure the resistance between connections 3BG and 3BL of component 149.
If the sensor resistance is not between:
741 Ω < X < 905 Ω at +20°C, replace the sensor.
Check the continuity and absence of interference resistance on the following connections:
•3BG between the components 120 and 149,
•3BL between components 120 and 149.
If the connection or connections are faulty and there is a repair procedure (see Technical Note 6015A, Electrical
wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check the conformity of the engine earths (oxidation, tightness, etc.).
Check the mounting and condition (overheating) of the sensor.
Check the low pressure circuit: run Test 3 Low pressure circuit check.
Apply the air flow checking procedure, (see conformity in the interpretation of statuses and parameters).
Check the turbocharger: apply Test 7 Variable geometry turbocharger control.
If the fault is still present, test the high pressure fuel circuit:
Run scenario SC035 High pressure fuel circuit fault finding.
To interpret the result, apply the interpretation of command SC035 (see Interpretation of commands).
EDC16CP33_V18_ALP05 / EDC16CP33_V1C_ALP05 / EDC16CP33_V54_ALP05 / EDC16CP33_V20_ALP05 / EDC16CP33_V58_ALP05 /
EDC16CP33_V5C_ALP05 / EDC16CP33_V24_ALP05 / EDC16CP33_V04_ALP05 / EDC16CP33_V08_ALP05 / EDC16CP33_V44_ALP05 /
EDC16CP33_V4C_ALP05 / EDC16CP33_V34_ALP05 / EDC16CP33_V38_ALP05 / EDC16CP33_V74_ALP05 / EDC16CP33_V28_ALP05 /
EDC16CP33_V62_ALP05 / EDC16CP33_V26_ALP05 / EDC16CP33_V60_ALP05
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-481
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP6 Fuel system leaks
NOTESBefore analysing this customer complaint, check that there are no faults, and the
conformity (or otherwise) of the parameters and statuses, using the diagnostic tool.
If the customer complaint is not eliminated, perform the following checks.
IMPORTANT:
Please observe the cleanliness guidelines and safety advice.
Procedure for checking for an external leak on the fuel circuit:
Clean away traces of grease with clean thinner and wipe the part or parts concerned with cleaning cloths.
Start the engine and increase the engine temperature until the diesel fuel reaches 40/50°C.
Stop the engine and check for traces of grease on the part or parts concerned.
If this is the case, replace the part or parts concerned.
Does the priming bulb show traces of grease?
(Visual and tactile inspections)
Check the assembly of the components and
the condition of the seal at the union of the two
components, if the leak is at the seal.
Replace the part or the parts concerned.
Bleed the fuel circuit and continue the checks.
Check the counter pressure valve located on
the fuel return line, after the injectors. Does the diesel filter show traces of grease?
(Visual and tactile inspections)
Do the fuel return pipes show traces of grease?
(Visual and tactile inspections)
YES
NO
YES
NO
YES
NO
A
EDC16CP33_V18_ALP06 / EDC16CP33_V1C_ALP06 / EDC16CP33_V54_ALP06 / EDC16CP33_V20_ALP06 / EDC16CP33_V58_ALP06 /
EDC16CP33_V5C_ALP06 / EDC16CP33_V24_ALP06 / EDC16CP33_V04_ALP06 / EDC16CP33_V08_ALP06 / EDC16CP33_V44_ALP06 /
EDC16CP33_V4C_ALP06 / EDC16CP33_V34_ALP06 / EDC16CP33_V38_ALP06 / EDC16CP33_V74_ALP06 / EDC16CP33_V28_ALP06 /
EDC16CP33_V62_ALP06 / EDC16CP33_V26_ALP06 / EDC16CP33_V60_ALP06
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-484
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP7 Rough idle
NOTESBefore analysing this customer complaint, check that there are no faults, and the
conformity (or otherwise) of the parameters and statuses, using the diagnostic tool.
If the customer complaint is not eliminated, perform the following checks.
Check the sealing and the condition of the
inlet circuit: run Test 4 Turbocharged air
inlet circuit check. Check the low
pressure circuit: run Test 3 Low pressure
circuit check. Check the engine parameters:
– Check the update of the engine management
computer calibration (last calibration).
– Check the conformity of the IMA* codes (see
Interpretation of commands, SC002 Enter injector
codes).
Check the charging circuit using Technical Note 6014A,
Charging circuit check, Alternator fault finding, 16A,
Alternator (formerly Technical Note 3455A).
– Check that the engine speed signal is correct using an
oscilloscope: no interference, broken tooth, etc.
– If not correct, check:
– The wiring.
– The flywheel position and the condition of the flywheel
teeth.
– Check the position and tightness of the engine speed
sensor. – Check the connections and wiring of the
injectors.
– Check the connections and wiring of the
engine management computer to the
injectors.
Check the high pressure circuit (external
leaks).
(see the end of the Fuel circuit external
leaks fault finding chart)
A
EDC16CP33_V18_ALP07 / EDC16CP33_V1C_ALP07 / EDC16CP33_V54_ALP07 / EDC16CP33_V20_ALP07 / EDC16CP33_V58_ALP07 /
EDC16CP33_V5C_ALP07 / EDC16CP33_V24_ALP07 / EDC16CP33_V04_ALP07 / EDC16CP33_V08_ALP07 / EDC16CP33_V44_ALP07 /
EDC16CP33_V4C_ALP07 / EDC16CP33_V34_ALP07 / EDC16CP33_V38_ALP07 / EDC16CP33_V74_ALP07 / EDC16CP33_V28_ALP07 /
EDC16CP33_V62_ALP07 / EDC16CP33_V26_ALP07 / EDC16CP33_V60_ALP07
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-485
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
IMA*: Individual injector correction
ALP7
CONTINUED
– Check the engine timing (and the
position of the high pressure pump
sprocket).
–Apply part B of Test 10 Poor injector
operation.
Check the lower engine:
– Check the engine mountings.
If the checks are correct, contact the
Techline.If fault DF308 Clogged particle filter is present,
consult the interpretation of DF308.
Run command SC036 Reinitialise programming and
select After particle filter replacement (see
Interpretation of commands).
A
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-486
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP8 Engine stalling
NOTESBefore analysing this customer complaint, check that there are no faults, and the
conformity (or otherwise) of the parameters and statuses, using the diagnostic tool.
If the customer complaint is not eliminated, perform the following checks.
Apply the interpretation of fault DF569 Turbocharging circuit to deal with ALP8.
EDC16CP33_V18_ALP08 / EDC16CP33_V1C_ALP08 / EDC16CP33_V54_ALP08 / EDC16CP33_V20_ALP08 / EDC16CP33_V58_ALP08 /
EDC16CP33_V5C_ALP08 / EDC16CP33_V24_ALP08 / EDC16CP33_V04_ALP08 / EDC16CP33_V08_ALP08 / EDC16CP33_V44_ALP08 /
EDC16CP33_V4C_ALP08 / EDC16CP33_V34_ALP08 / EDC16CP33_V38_ALP08 / EDC16CP33_V74_ALP08 / EDC16CP33_V28_ALP08 /
EDC16CP33_V62_ALP08 / EDC16CP33_V26_ALP08 / EDC16CP33_V60_ALP08
EDC16CP33
Program No.: C4
Vdiag No.: 04, 08, 18, 1C,
20, 24, 26, 28, 34, 38, 44,
4C, 54, 58, 5C, 60, 62, 74

13B-487
AFTER REPAIRCarry out a road test, then check with the diagnostic tool.
V12 MR-372-J84-13B300$170.mif
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
ALP9 PARTICLE FILTER WARNING LIGHT COMES ON TOO OFTEN
NOTESBefore dealing with this customer complaint, check that there are no faults except
DF312 Speed request, and the conformity (or otherwise) of the "parameters" and
"statuses" using the diagnostic tool. Deal with the other faults first.
If the customer complaint is not eliminated, perform the following checks.
Have the last 10 regeneration
attempts failed?Are all the regeneration failures
linked to engine cut-off?
See group parameter (ET706
Stored engine status no. 1 to
ET715 Stored engine status no.
10)
(e.g. ET706 STOPPED)Output 1 Is the distance of PR412 Distance of
last successful regeneration less
than all the parameters of group 2?
(PR794 to PR803 Stored
regeneration failure no.1 to no.10)
Is at least one status for group
1 = STATUS4?Check the exhaust pipe for leaks
or blockage. Repair if necessary.
Carry out an After-Sales
regeneration if not already
performed. To do this, see SC017
Particle filter regeneration in
Interpretation of commands.Output 2
YES
YES
NONO
YES
A
NO
B
EDC16CP33_V18_ALP09 / EDC16CP33_V1C_ALP09 / EDC16CP33_V54_ALP09 / EDC16CP33_V20_ALP09 / EDC16CP33_V58_ALP09 /
EDC16CP33_V5C_ALP09 / EDC16CP33_V24_ALP09 / EDC16CP33_V28_ALP09 / EDC16CP33_V62_ALP09 / EDC16CP33_V26_ALP09 /
EDC16CP33_V60_ALP09
EDC16CP33
Program No.: C4
Vdiag No.: 18, 1C, 20, 24,
26, 28, 54, 58, 5C, 60, 62