DIESEL INJECTION
Fault finding – Interpretation of commands13B
13B -217V3 MR-372-J84-13B250$765.mif
EDC16
PROGRAM No: C1
Vdiag No.: 51
* Opening cyclic ratio signalAC004
CONTINUED
Turbocharger control circuit check (continued)
4) Turbocharger operation check:
a) Connect a vacuum pump to the hose connected to the turbocharger control diaphragm.
Apply a negative pressure of 800 ± 100 mbar:
If there is a leak, replace the turbocharger (diaphragm included).
b) Check the control rod movement and setting (see MR 364, Mechanics, 12B, Turbocharging).
If the control rod is sticking, replace the turbocharger.
c) Engine cold and stopped:
Remove the turbocharger inlet duct and check that the compressor turns freely on the axis.
d) If the fault persists:
Check that the exhaust manifold is not leaking.
Check that the exhaust is not blocked.
Carry out the necessary repairs.
5) Computer output stage check: (solenoid valve connected).
This operation can only be carried out if the checks indicated in step no. 2 are not conclusive.
Either with the voltmeter: Connect the voltmeter earth lead on track 2 of the solenoid valve and the positive
lead on track 1.
Clear any solenoid valve fault then run command AC004:
●The voltmeter should display ten cycles of two successive voltages ~ = battery voltage X opening cycle ratio*
in process.
that is: ~ 2.5 V (opening cyclic ratio* of 20%) then ~ 8.7 V (opening cyclic ratio* of 70%).
Or with the oscilloscope (at 5 V range/division and 1 ms/div time base): Connect the earth lead of the
oscilloscope to the battery earth and the positive test pin to track 2 of the solenoid valve.
Clear any solenoid valve faults, then run command AC004:
●the oscilloscope should display a square wave signal of 12.5 V in amplitude at a frequency of 140 Hz
(with an opening cyclic ratio* passing from ~ 20 to ~ 70%).
If the measurement is correct, replace the solenoid valve.
If the measurement does not show any control or continuous voltage, contact the Techline.
DIESEL INJECTION
Fault finding – Fault Finding Chart13B
13B -225V3 MR-372-J84-13B250$855.mif
EDC16
PROGRAM No.: C1
Vdiag No.: 51
ALP2
CONTINUED 1
Check that the heater plugs are actuated using the AC001 Preheating unit command.
Check the sealing and condition of the inlet circuit: run test 3 Turbocharged air inlet circuit check and follow the
fault finding procedure.
Check that there are no foreign bodies on the flowmeter grille: run test 4 Air flowmeter and follow the fault finding
procedure.
Check that the exhaust is not blocked: run test 1 Exhaust pipe check and follow the related fault finding
procedure.
Check the consistency of the signal from the engine coolant temperature sensor.
Check the pressure regulator is working properly (see command AC011 Rail pressure regulator).
Check the operation of the injectors (excessive return leak, clogging, seizing): run test 8 Poor injector operation.
Check the engine timing (and the position of the high pressure pump sprocket).
Check the balance of the compressions, according to the power consumption during the starting phase
(Compression test menu on the CLIP Technic tool).
If you do not have the CLIP Technic or if there is an imbalance, use a compression gauge to get an accurate
measurement.
after the operation, clear the faults caused by disconnecting the regulator and the heater plugs.
End of part A
AFTER REPAIRcarry out a road test followed by a complete check with the diagnostic tool.
