939003568 - D004 ENGINE NOT RUNNING SMOOTHLY

There are decreases in performance during acceleration
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Check, in order:

  • the condition of the air intake circuit
  • that there are no faults in the air filter
  • whether the diesel pipes are leaking
  • the accelerator pedal travel
  • that there is no water, petrol, paraffin or dirt in the fuel tank and filter
  • that there no obstructions in the exhaust system
Continue to Step 1Fault in air intake circuitRepair the air intake circuit
Air filter blockedReplace the filter element
Leak from diesel pipesEliminate the leaks
Accelerator pedal travel incompleteEliminate the cause of the problem
Presence of water, petrol, paraffin or dirt detectedClean the tank and pipes and replace the filter element
Obstruction in the exhaust systemReplace the damaged system component
1CHECKING 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 all the parameters
Continue to Step 2An error is detected in the control unitContinue following the instructions for the diagnostic equipment
unreliable parametersContinue following the instructions for the diagnostic equipment
2CHECK EGR AND ADJUST TURBOCHARGERAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket.Carry out active diagnosis of EGR solenoid valveCarry out active diagnosis of the turbocharger regulator solenoid valveCheck operation of the variable geometry control actuator See Test    1064BC Variable geometry turbocharger actuator leakage testContinue to Step 3EGR solenoid valve not workingCheck the continuity of the wiring See    E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT, if necessary, replae the solenoid valve Op.    1080C74
Turbocharger solenoid valve not workingCheck the continuity of the wiring See    E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT, if necessary, replae the solenoid valve Op.    1064A28
Actuator does not work correctlyCheck the condition of the vacuum circuit and, if necessary, replace the damaged components
3ROAD TEST WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Road test the vehicle, reproducing the conditions in which the fault arises, keeping the diagnostic equipment connected.

Check:

  • for errors in the control unit
  • plausibility of all the parameters
Continue to Step 4An error is detected in the control unitContinue following the instructions for the diagnostic equipment
Unreliable parametersContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unitRestore the connection between the engine management control unit and the diagnostic connector.
4CHECK ON TURBOCHARGERAll OKProblems metOperation
Check the operation of the turbocharger as described in the Test See Test    1064BA Check the supercharging pressureContinue to Step 5Turbocharger faultyReplace the turbocharger unit
5CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer present Fault persists: control unit faultyReplace control unit Op.    1060G80 Search for the fault starting from another symptom''