125000495 - 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
  • The seal of the diesel pipes
  • That there is no water, petrol, paraffin or dirt in the fuel tank and filter
  • That the battery earth is correctly fixed
  • 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.    Op. 1048A14 AIR CLEANER FILTERING ELEMENT - REPLACE.
Leak from diesel pipesEliminate the leaks
Presence of water, petrol, parffin or dirt detected.Clean the tank and pipes and replace the filter element Op.    Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
Loose battery earth terminalRestore the correct fixing of the earth cable
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 the control unit;
  • The plausibiilty of 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
2ROAD TEST WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Road test the vehicle, reproducting the conditions in which the fault arises, keeping the diagnostic socket connected

Check:

  • For errors in the control unit;
  • The plausibiilty of the parameters
Continue to Step 3An 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.
3Continue as instructed by the testerAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace control unit Op.    Op. 1060G80 DS ELECTRIC INJECTION CONTROL UNIT - R R
During driving, the engine misses and loses performance
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • The condition of the air filter;
  • That the battery is properly connected to earth See    See E1010 SUPPLY
Continue to Step 1Filter element dirty, damaged or incorrectly fittedReplace or refit filter element correctly Op.    Op. 1048A14 AIR CLEANER FILTERING ELEMENT - REPLACE.
Earth fastening not correctRenew the wiring See    See E1010 SUPPLY
1CHECK 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
  • The plausibiilty of the parameters
Continue to Step 2Supply system error detectedContinue according to the instructions inSee table    See table Z50 MIXTURE STRENGTH ERROR
Upstream Lambda sensor error detectedContinue according to the instructions inSee 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 under which the fault arises, keeping the diagnostic equipment connected

Check:

  • That there are no faults in the engine management control unit
  • The plausibiilty of the parameters
Continue to Step 3Supply system error detectedContinue according to the instructions inSee table    See table Z50 MIXTURE STRENGTH ERROR
Upstream Lambda sensor error detectedContinue according to the instructions inSee 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 fuel supply presure, on road if necessary (to reproduce the conditions under which the fault arises) Op.    Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSUREContinue 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.    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GUAGE CONTROL - R + R
4CHECK AIR CONDITIONING SYSTEMAll OKProblems metOperation
Road-test the car and to see if the anomalous behaviour is affected by air conditioner activationContinue to Step 5Fault present only with the air conditioner onContinue according to the instructions inSee table    See table L10 CLIMATE CONTROL NOT COOLING
5CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace control unit Op. 1056B82