Page 224 of 269

13B-224V6 MR-413-X44-13B000$190.mif
DIESEL INJECTION
Fault finding – Tests13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
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:
–compressor outlet pipe to the turbocharging air cooler (on some engines,
the turbocharging air cooler does not exist),
–outlet pipe of the turbocharging air cooler to the inlet manifold,
–inlet manifold,
–pressure and temperature sensors.
Is one of these components incorrect (pipes dislodged, torn, bent,
pierced or kinked)?Replace the faulty
parts (see MR 364
(Mégane II), 370
(Scénic II), 392
(Clio III), 385
(Modus),
411 (New Twingo) or
417 (Kangoo II),
Mechanical, 12B
Turbocharging).
Exhaust circuit 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,
–pressure and temperature sensors connected.
Do certain of these components have blackish or whitish traces?
Run test 10 Turbocharger solenoid valve check.
A
YES
NO
YES
NO
Page 225 of 269

13B-225V6 MR-413-X44-13B000$190.mif
DIESEL INJECTION
Fault finding – Tests13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
TEST 12 Turbocharger
IMPORTANT
Perform these checks without removing the turbocharger and with the vehicle ignition switched off.
Checking the turbocharger shaft
WARNING
Observe the following safety precautions:
–wear high temperature protective gloves when the engine is hot,
–do not wear oversize or baggy clothing or hanging jewellery,
–watch out for possible triggering of the motor-driven cooling fan unit and the operation of the accessories belt
or belts.
Note:
The turbocharger shaft is the shaft that connects the compressor wheel and the turbine wheel.
Depending on the vehicle type, the best visual access will be either from above or from below.
Disconnect the air pipe located between the turbocharger and the air filter.
Wearing gloves, check the operation of the turbocharger shaft by turning the vanes manually without forcing.
Does the shaft have a kickdown point in rotation?
Does the compressor wheel touch the casing of the turbocharger?
If for these 2
questions the
response is NOIf YES for one of these 2 questions
Replace the turbocharger (see MR 364 (Mégane II), 370 (Scénic II) 392
(Clio III), 385 (Modus), 411 (New Twingo) or 417 (Kangoo II),
Mechanical, 12B, Turbocharging, Turbocharger: Removal -
Refitting and Technical Note 3938A, Broken turbocharger:
Replacement instructions).
A
DCM1.2_V48_TEST12/DCM1.2_V4C_TEST12/DCM1.2_V50_TEST12/DCM1.2_V54_TEST12/DCM1.2_V58_TEST12/DCM1.2_V5C_TEST12
Page 235 of 269

13B-235V6 MR-413-X44-13B000$200.mif
13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
NOTESSpecial note:
Only consult this customer complaint after a full check with the diagnostic tool.
No dialogue with the computer ALP1
Starting fault:
The engine will not start ALP2
The engine starts with difficulty, or starts then stalls ALP3
Starting difficult with warm engine ALP4
Rough idle (pumping) ALP5
Idling speed too high or too low ALP6
Behaviour while driving:
Erratic acceleration/deceleration and engine racing ALP7
Acceleration gap ALP8
Engine cut-out (stalling) ALP9
Engine bucking ALP10
Loss of power ALP11
Too much power ALP12
Excessive consumption ALP13
Overspeed when releasing accelerator or changing gear ALP14
Engine dies on pulling away ALP15
Noise, odours or smoke:
Knocking engine, noisy engine, noise from the turbocharger ALP16
Blue, white or black smoke ALP17
Oil leaks from the turbocharger ALP18
DIESEL INJECTION
Fault finding – Customer complaints
Page 236 of 269

13B-236V6 MR-413-X44-13B000$210.mif
13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
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).
Run 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, earth bolts secure on the battery terminal).
Check that the supply to the computer is correct:
For New Twingo:
–AP29 between components 1016 and 120,
–3FB between components 238 and 120,
–NH between earth and component 120,
For Mégane II, Scénic II, Modus, and Clio III:
–AP15 between components 1337 and 120,
–NH between earth and component 120,
–3FB1 between components 1337 and 120,
–3FB2 between components 1337 and 120.
For Kangoo 2:
–AP15 between components 1337 and 120,
–N between earth and component 120,
–3FB between components 1337 and 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 Techline.
DCM1.2_V48_ALP1/DCM1.2_V4C_ALP1/DCM1.2_V50_ALP1/DCM1.2_V54_ALP1/DCM1.2_V58_ALP1/DCM1.2_V5C_ALP1
DIESEL INJECTION
Fault finding – Fault finding charts
Page 237 of 269

13B-237V6 MR-413-X44-13B000$210.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
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: run TEST 5 Air inlet circuit check.
Is the catalytic converter clogged or damaged?Replace the catalytic converter (see MR
364 (Mégane II), MR 370 (Scénic II),
MR 385 (Modus), MR 392 (Clio III), MR
411 (New Twingo), MR 417 (Kangoo 2),
Mechanical, 19B, Exhaust, Catalytic
converter: Removal - Refitting).
Check the electrical circuit: run 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
DCM1.2_V48_ALP2/DCM1.2_V4C_ALP2/DCM1.2_V50_ALP2/DCM1.2_V54_ALP2/DCM1.2_V58_ALP2/DCM1.2_V5C_ALP2
Page 238 of 269
13B-238V6 MR-413-X44-13B000$210.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
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: run TEST 1 Low pressure circuit check.
Check the injectors: run TEST 3 Injector check.
A
NO
YES
NO
YES
YES
NO
B
Page 240 of 269

13B-240V6 MR-413-X44-13B000$210.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
ALP3 The engine starts with difficulty, or starts then stalls
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: run test 5 Air inlet circuit check.
Is the catalytic converter clogged or damaged?Replace the catalytic converter (see MR 364
(Mégane II), MR 370 (Scénic II), MR 385
(Modus), MR 392 (Clio III), MR 411
(New Twingo), MR 417 (Kangoo 2),
Mechanical, 19B, Exhaust, Catalytic
converter: Removal - Refitting).
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.
Is the compression in order? Carry out the necessary repairs.
Visually check the condition of the engine wiring harness.
YES
NO
NO
YES
NO
YES
A
DCM1.2_V48_ALP3/DCM1.2_V4C_ALP3/DCM1.2_V50_ALP3/DCM1.2_V54_ALP3/DCM1.2_V58_ALP3/DCM1.2_V5C_ALP3
Page 242 of 269

13B-242V6 MR-413-X44-13B000$210.mif
DIESEL INJECTION
Fault finding – Fault finding charts13B
DCM 1.2 Injection
Program No.: 4D
Vdiag No.: 48, 4C, 50,
54, 58, 5C
ALP4 Starting difficult with warm engine
NOTESOnly consult this customer complaint after a full 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 air inlet circuit: run TEST 5 Air inlet circuit check.
Is the compression in order? Carry out the necessary repairs.
Is the timing set correctly? 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.
Visually check the condition of the engine wiring harness.
Check the low pressure circuit: run TEST 1 Low pressure circuit check.
NO
YES
NO
YES
A
DCM1.2_V48_ALP4/DCM1.2_V4C_ALP4/DCM1.2_V50_ALP4/DCM1.2_V54_ALP4/DCM1.2_V58_ALP4/DCM1.2_V5C_ALP4