184000412 - D01 ENGINE NOT RUNNING SMOOTHLY / (HESISTANT)

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

Preliminarily check:

  • the state of the spark plugs and leads;
  • the condition of the air intake circuit
Continue to Step 1Spark plugs dirty or damagedReplace the spark plugs Op. 5510D10
Spark plug leads damagedReplace the spark plug leads Op. 5510D14
Air intake circuit faultRestore the correct operation of the intake circuit
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the Examiner diagnostic equipment 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 detectedCoolant leaks detectedSee table Z50
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 3Error arises suddenly in the control unitContinue following the instructions for the diagnostic equipment
Inconsistent parameterContinue following the instructions for the diagnostic equipment
3CHECK ON FUEL PRESSUREAll OKProblems metOperation
Carry out a road test, reproducing the conditions in which the fault arises.Check the fuel supply pressure Op. 0510C10 Continue to Step 4Incorrect pressure: obstructions in the fuel delivery pipeRemove the obstructions in the fuel pipe, and if necessary replace it
Pressure not correct: tank insufficiently ventilatedRestsore the tank ventilation
Pressure not correct: fuel pump electrical circuit brokenRepair fuel pump electrical circuit
Pressure incorrect: fuel pump damagedReplace fuel pump assembly
4CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace control unit Op. 1056B82