2398742 - D03 ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

During driving, the engine misses and loses performance
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
  • that the battery earth is correctly fixed
  • 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 Op.   1048A14 
Leak from diesel pipesstop the leak
Loose battery earth terminalRestore the correct fixing of the earth cable
Presence of water, petrol, paraffin or dirt detectedClean the tank and pipes and replace the filter element Op.   1048A14 
Obstruction in the exhaust systemReplace the damaged system component
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Connect the Examiner diagnostic equipment to the diagnostic socket and check:

  • that there are no errors in the control unit
  • absence of errors between the engine control unit and the ABS control unit, particularly error U1706
Continue to Step 2Presence of error P0093Continue to Step 2
For the presence of one of the following errors:P0262, P0265, P0268, P0271 Continue to Step 3
Presence of error P0704Continue to Step 4
Presence of one of the following errors: P0120, P0220, P0226Continue to Step 5
Presence of one of the following errors: P0101, P1102Continue to Step 6
Presence of communication errors between the engine control unit and ABS control unit Check wiring continuity See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT
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 the diesel pressure parameter is as described in the test 1060D
  • the correct operation of the pressure regulator by means of active diagnostics
  • absence of leaks in high pressure circuit
  • the correct operation of the injectors through active diagnosis
Continue to Step 3Diesel pressure parameter incorrectContinue to Step 3
Pressure regulator defectiveReplace the pressure regulator Op.   1060E50 
Leaks in high pressure circuitRestore system seal
Faulty injectorReplace the damaged injector Op.   1060F10 
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 4Consistent leak from one injectorReplace the injector Op.   1060F10 
4CHECK CLUTCH SWITCHAll OKProblems metOperation

With the Examiner tester connected, check:

  • correct positioning of switch on clutch pedal
  • correct operation of clutch switch
Continue to Step 5Incorrect switch positionPosition the switch correctly
Faulty switch operationReplace switch Op.   1060G42 
5CHECK 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 6Incorrect potentiometer operationReplace potentiometer Op.   1068A20 
Electrical wiring defectiveRenew the wiring See   E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT
6FLOW METER CHECKAll OKProblems metOperation
Check the correct operation of the flow meter as described in the test See Test   1060GB  Check on operation of air flow meter Continue to Step 7Faulty flow meter operationReplace the flow meter Op.   1060G10 
7CHECK HIGH PRESSURE PUMPAll OKProblems metOperation
Connect the Examiner tester and carry out a road test. Check the diesel pressure changes in accordance with rpm/load.Continue to Step 8Unstable rail pressure caused by defective high pressure pump.Replace high pressure pump Op.   1060E10 
8CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace control unit Op.   1060G80