2751024 - D04 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 1Intake air circuit ducts obstructedRepair the air intake circuit
Leaks from intake ducts after the compressorRepair the leak
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
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket

Check:

  • for errors in control unit;
Continue to Step 2Presence of error P0093Continue to Step 2
Presence of one of the following errors: P0262, P0265, P0268, P0271 Continue to Step 3
Presence of error P0504Continue to Step 4
Presence of error P1237 or P0400Continue to Step 6
Presence of one of the following errors: P0101, P1102 Continue to Step 7
Presence of one of the following errors: P0120, P0220, P0226Continue to Step 8
Presence of other errorsContinue according to the instructions for the diagnostic equipment
2HIGH RESSURE CIRCUIT CHECKAll OKProblems metOperation

With the Examiner tester connected to the tester input check:

Check that there are no leaks in high pressure circuit
Continue to Step 4Diesel pressure parameter incorrectContinue to Step 3
Pressure regulator defectiveReplace the pressure regulator
Leaks in high pressure circuitRestore system seal
3INJECTOR HIGH PRESSURE CHECKAll OKProblems metOperation
Check, as described in the test See Test   1060C  Injector high pressure fuel circuit check , that diesel leaks from the injector recirculation connections are small and about the same as one another.Continue to Step 4Large leak from one injectorReplace the injector
4BRAKE SWITCH CHECKAll OKProblems metOperation
With the Examiner connected to the diagnostic socket, check that the brake switch is working properlyContinue to Step 5Faulty switchReplace switch
Faulty wiringRenew the wiring See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT
5CHECK FUEL PUMPAll OKProblems metOperation
Use an Examiner to check fuel pump power uptake is correct by performing the test See Test   1040AA  Check supply voltage and absorption current Continue to Step 6Absorption not correctReplace the pump
6CHECK EGRAll OKProblems metOperation

With an Examiner connected to the tester output, perform:

  • active testing of the electric EGR valve
Check the condition of the EGR system, particularly to ensure that the EGR is not blocked open
Continue to Step 7EGR wiring brokenRestore correct operation See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT
EGR valve faultReplace EGR Op. 1080C74
EGR system mechanical faultRestore correct operation
7CHECK FLOW METERAll OKProblems metOperation
Check that the flow meter is working properly by carrying out the test See Test   1060GB  Check on operation of air flow meter Continue to Step 8Flow meter signal too high with consequent increased exhaust gas recirculationReplace the flow meter
8CHECK ACCELERATOR PEDAL POTENTIOMETERAll OKProblems metOperation
Check the correct operation of the accelerator pedal potentiometer as described in the test See Test   1068AB  Check operation of accelerator pedal potentiometer Continue to Step 9Anomalous potentiometer operationReplace potentiometer
Electrical wiring defectiveRenew the wiring See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT
9CHECK ON TURBOCHARGERAll OKProblems metOperation
Check the operation of the turbocharger as described in the Test See Test   1064BA  Check turbo presure Continue to Step 11Turbocharger faultyReplace the turbocharger unit
10CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace control unit Op.   1060G80