3022581 - D03 ENGINE NOT RUNNING SMOOTHLY / (IRREGULAR OPERATION)

During driving, the engine misses and loses performance
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • the condition of the air filter
  • battery earth correctly fixed See   E1010  SUPPLY
Continue to Step 1Filter element dirty, damaged or incorrectly fittedReplace or refit filter element correctly Op.   1048A14 
Earth fastening not correctRenew the wiring
1CHECKING WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket.

Check:

  • that there are no faults in the engine management control unit;
  • plausibility of all the parameters
Continue to Step 2'Supply system' error detectedContinue as instructed in the Table See table   Z50  MIXTURE STRENGTH ERROR
'Upstream lambda sensor' error detectedContinue as instructed in the Table See table   Z56  UPSTREAM LAMBDA SENSOR SIGNAL ERROR
Another error dectected in the control unitContinue following the instructions for the diagnostic equipment
Inconsistent parameterContinue following the instructions for the diagnostic equipment
2ROAD TEST WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Road test the vehicle, reproducing the conditions in which the fault arises, keeping the diagnostic equipment connected.

Check:

  • that there are no faults in the engine management control unit;
  • plausibility of all the parameters
Continue to Step 3'Supply system' error detectedContinue as instructed in the Table See table   Z50  MIXTURE STRENGTH ERROR
'Upstream lambda sensor' error detectedContinue as instructed in the Table See table   Z56  UPSTREAM LAMBDA SENSOR SIGNAL ERROR
Sudden occurrence of another error in the control unit detectedContinue following the instructions for the diagnostic equipment
Inconsistent parameterContinue following the instructions for the diagnostic equipment
3CHECK ON FUEL PRESSUREAll OKProblems metOperation
Check, if necessary on the road (to reproduce the conditions in which the fault arises), the fuel supply pressure Op.   0510C10  Continue to Step 4Pressure not correct: obstructions in fuel delivery pipeRemove the obstructions in the fuel pipe, and if necessary replace it
Pressure incorrect: fuel pump damagedReplace fuel pump assembly Op.   1040A70 
4CHECK AIR CONDITIONING SYSTEMAll OKProblems metOperation
Road test the vehicle and check whether the fault is affected by whether or not the air conditioner is switched onContinue to Step 5Fault present only with the air conditioner onContinue as instructed in the Table See table   L10  CLIMATE CONTROL NOT COOLING
5CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Road test the vehicle and check whether the fault is affected by whether or not the air conditioner is switched onEnd of diagnosisFault persists: control unit faultyReplace control unit Op.   1056B82