184000416 - D05 ENGINE DOES NOT PRODUCE BEST PERFORMANCE

.
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Check, in order:

  • the condition of the air intake circuit
  • no faults in the air filter;
  • seal of the diesel pipes;
  • accelerator pedal travel;
  • absence of obstructions in the catalytic converter
Continue to Step 1Fault in air intake circuitRepair the air intake circuit
Air filter blockedReplace the filter element Op. 1048A14
Leaks from the diesel pipesEliminate the leaks
Accelerator pedal travel incompleteEliminate the cause of the problem
Catalyzer obstructedReplace the catalyzer Op. 1080B62
Operation incorrectContinue to Step 1
1CHECK TURBOCHARGER ADJUSTMENTAll OKProblems metOperation
With the diagnostic equipment, carry out active diagnosis on the turbocharger regulating solenoidCheck the operation of the variable geometry control actuator by carrying out the test See Test 1064BC Variable geometry turbocharger actuator leakage test Continue to Step 2Solenoid not workingCheck the continuity of the wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT and if necessary replace the solenoid Op. 1064B34
Actuator does not work correctlyCheck the condition of the vacuum circuit and, if necessary, replace the damaged components
2CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket

check

  • for errors in the control unit
  • plausibility of parameters;
  • carry out active diagnosis of E.G.R. solenoid
Continue to Step 3An error is detected in the control unitContinue following the instructions for the diagnostic equipment
unreliable parametersContinue following the instructions for the diagnostic equipment
E.G.R. solenoid not workingCheck wiring continuity See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
E.G.R. solenoid not workingReplace the solenoid valve Op. 1080C24
3ROAD TEST WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Road test the vehicle keeping the diagnostic instrument connected.
Make sure that the conditions in which the problem occurs are reproduced

Check:

  • for errors in the control unit
  • plausibility of all the parameters
Continue to Step 4Errors suddenly occur in the control unitContinue following the instructions for the diagnostic equipment
Parameters off scaleContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unitRestore the connection between engine management control unit and diagnostic connector See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
4CHECK ON BRAKE PEDAL SWITCHAll OKProblems metOperation
Check that the brake pedal switch is working properlyContinue to Step 5Brake pedal does not returnEliminate the cause of the sticking
Switch stuck in closed positionReplace the switch Op. 1060G38
Wiring short circuitedRestore the correct connection
5CHECK ON TURBOCHARGERAll OKProblems metOperation
Check the operation of the turbocharger as described in the Test See Test 1064BA Check turbo presure Continue to Step 6Turbocharger faultyReplace the turbocharger Op. 1064A19
6HIGH PRESSURE CHECKAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socketCheck as described in the test See Test 1060D Check high pressure fuel circuit that the diesel pressure parameter is correctContinue to Step 14Pressure not correctContinue to Step 7
7CHECK ON RETURN LOW PRESSUREAll OKProblems metOperation
Check as described in the test See Test 1060A Low return fuel pressure circuit check that the pressure in the return pipe to the tank is under 1 barContinue to Step 8Pressure above maximum limit: return pipe to tank blockedRepair the pipe, if necessary, replace it.
8LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check as described in the test See Test 1060B Low fuel pressure supply circuit check that the diesel pressure between filter and pressure pump is between 2 and 3 barContinue to Step 14Pressure below minimum limit or above maximum valueContinue to Step 9
9LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Choke the return pipe and repeat the test See Test 1060B Low fuel pressure supply circuit check with the pipe choked, checking that the pressure at the filter outlet remains below 2 barContinue to Step 10Pressure rises to 5 bar: blocked pressure regulation valve on filter supportReplace the valve Op. 1044B16
10CHECK DELIVERY LOW PRESSUREAll OKProblems metOperation
Check that the difference in pressure upstream and downstream of the filter is less than 1 barContinue to Step 11Difference in pressure greater than 1 barReplace the fuel filter cartridge Op. 1044B20
11CHECK ON RETURN LOW PRESSUREAll OKProblems metOperation
Check that the pressure downstream of the supply pump is over 2.2 barContinue to Step 14Pressure below 2 barContinue to Step 12
12LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Measure the difference in pressure between the electric pump outlet and filter inlet, checking that it is less than 0.3 barContinue to Step 13Difference in pressure greater than 0.3 barReplace the pipe
13LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check as described in the test See Test 1060A Low return fuel pressure circuit check that the pump's supply voltage is 12V and that the absorbed current is between 2 and 10 amps.Continue to Step 14Voltage < 12 VCheck electric wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
Current > 10 Amp: pump defectiveReplace the fuel pump assembly Op. 1040A70
Current < 2 Amp.: pump blockedReplace the fuel pump assembly Op. 1040A70 and clean the fuel tank
14CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Replace the DRV pressure regulating valve and check that the fault is no longer presentEnd of diagnosisFault persistsContinue to Step 15
15Continue as instructed by the testerAll OKProblems metOperation
Replace the pressure pump and check that the fault is no longer presentEnd of diagnosisFault persistsContinue to Step 16
16CHECK ON TIMINGAll OKProblems metOperation
Check that the timing is correct Op. 0510A20 Continue to Step 17Timing not correctRestore the correct timing
17VALVE CLEARANCE CHECKAll OKProblems metOperation
Check that the valve tappet clearance is correct. Op. 1036H14 Continue to Step 18Valve clearance not correctAdjust the tappets Op. 1036H10
18CHECK ON CYLINDER COMPRESSIONAll OKProblems metOperation
Carry out the cylinder compression test Op. 0520G15Continue to Step 20Cylinder compression insufficientContinue to Step 19
19CHECKING CAUSE OF INSUFFICIENT COMPRESSIONAll OKProblems metOperation
Carry out R.R. on head to check the valve seal and check the condition of the cylinders/piston ringsContinue to Step 20Insufficient valve sealOverhaul the cylinder head
20CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace engine management control unit Op. 1060G80