125000499 - D21 ENGINE CUTS OUT WHILST DRIVING

The engine cuts out suddenly whilst driving. Later, after starting normally, it works again
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • That there is fuel in the tank;
  • That the engine wiring is properly connected to earth;
  • That the battery earth is correctly fixed;
  • The correct fixing of positive battery terminal and that all leads are connected;
  • that there is no water in the fuel filter
Continue to Step 1No fuelIntroduce fuel
Fastenings slack or oxidizedRe-attach correctly
Presence of water in the fuel filterClean the tank and pipe and replace the filter element Op.    Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socketCheck that there are no errors in the control unitContinue to Step 2An error is detected in the control unitContinue 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 connectedCheck that there are no errors stored in the control unit memoryContinue to Step 3An error is detected in the control unitContinue following the instructions for the diagnostic equipment
3INJECTOR HIGH PRESSURE CHECKAll OKProblems metOperation
Check, as described in the See Test    See Test 1060C INJECTOR HIGH PRESSURE, FUEL CIRCUIT LEAKAGE TEST, 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.    Op. 1060F10 FUEL INJECTORS
4HIGH PRESSURE CHECKAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socketCheck as described in the See Test    See Test 1060D ELECTRONIC DIESEL INJECTION CONTROLthat the diesel pressure parameter is correctContinue to Step 12Pressure not correctContinue to Step 5
5CHECK ON RETURN LOW PRESSUREAll OKProblems metOperation
Check as described in the See Test    See Test 1060A LOW RETURN FUEL PRESSURE CIRCUIT CHECKthat the pressure in the return pipe to the tank is under 1 barContinue to Step 6Pressure above maximum limit: return pipe to tank blockedRepair the pipe; if necessary replace it
6LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check as described in the See Test    See Test 1060B LOW FUEL PRESSURE SUPPLY CIRCUIT CHECKthat the diesel pressure between filter and pressure pump is between 2 and 3 barContinue to Step 12Pressure below minimum limit or above maximum limitContinue to Step 7
7LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Choke the return pipe from the pressure regulating valve and repeat the See Test    See Test 1060B LOW FUEL PRESSURE SUPPLY CIRCUIT CHECKwith the pipe choked, checking that the pressure at the filter outlet is below 2 barContinue to Step 8Pressure rises to 5 bar: blocked pressure regulation valve on filter supportReplace the valve Op.    Op. 1044B16 DELIVERY ADJUSTMENT VALVE - R R
8LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check that the difference in pressure upstream and downstream of the filter is less than 1 barContinue to Step 9Difference in pressure greater than 1 barReplace the diesel filter cartridge Op.    Op. 1044B20 FUEL FILTER FILTERING ELEMENT - REPLACE
9LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check that the supply pump pressure at the filter inlet is over 2.2 barContinue to Step 12Pressure below 2.2 barContinue to Step 10
10LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Measure the difference in pressure between electric pump outlet and filter inlet, checking that it is less than 0.3 barContinue to Step 11Difference in pressure greater than 0.3 barReplace the pipe
11LOW SUPPLY PRESSURE CHECKAll OKProblems metOperation
Check as described in the that the pump''s supply voltage is 12V and that the absorbed current is between 2 and 10 amps.Continue to Step 12Voltage < 12 VCheck electric wiring See    See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT
Current > 10 Amp: pump defectiveReplace the fuel pump assembly Op.    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GUAGE CONTROL - R + R
Current < 2 Amp.: pump blockedReplace fuel pump assembly Op.    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GUAGE CONTROL - R + Rand clean the fuel tank
12CORRECT OPERATION CHECKAll OKProblems metOperation
Replace the DRV pressure regulator and check that the fault is no longer presentEnd of diagnosisFault persistsContinue to Step 13
13CORRECT OPERATION CHECKAll OKProblems metOperation
Replace the pressure pump and check that the fault is no longer presentEnd of diagnosisFault persistsContact Technical Service for further information on the problem
The engine cuts out suddenly whilst driving. Later, after starting normally, it works again
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation

Preliminarily check:

  • That the earth is correctly fixed on the engine;
  • That the battery earth is correctly fixed See    See E1020 EARTHS;
  • The correct fixing of the positive battery terminal and the leads connected to it See    See E1010 SUPPLY;
  • Control unit supply (including ignition switch)
Continue to Step 1Earth leads incorrectly fixedRenew or, if necessary, replace the battery earth lead Op.    Op. 5530B22 BATTERY EARTH LEAD - R+R
Battery positive earth incorrectly fixedRestore battery positive lead Op.    Op. 5530B26 LEAD BETWEEN BATTERY AND STARTER MOTOR - R+R
Inconsistent supplyRenew supply/earth
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
  • Plausibility of all the parameters
Continue to Step 2An error is detected in the control unitContinue according to the instructions for the diagnostic equipment
Inconsistent parameterContinue according to the instructions for the diagnostic equipment
2ROAD TEST WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
2.0 JTSRoad 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 plausibility of all the parameters, in particular
  • Rail pressure - rail pressure setting
Continue to Step 3Error suddenly occurs in the control unitContinue according to the instructions for the diagnostic equipment
Inconsistent parameterContinue according to the instructions for the diagnostic equipment, analysing the causes that have led to the inconsistency
Loss of dialogue between the control unit and diagnostic instrumentRestore the control unit circuit supply See    See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
3.2 V6Road test the vehicle, reproducting the conditions in which the fault arises, keeping the diagnostic socket connected

check

  • That there are no faults in the engine management control unit
  • Plausibility of all the parameters
Continue to Step 5Error suddenly occurs in the control unitContinue according to the instructions for the diagnostic equipment
Inconsistent parameterContinue according to the instructions for the diagnostic equipment
Loss of dialogue between the control unit and diagnostic instrumentRestore the control unit circuit supply See    See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
3LOW FUEL PRESSURE CIRCUIT CHECKAll OKProblems metOperation
Road test the vehicle and check the fuel supply pressure
Make sure to reproduce the conditions in which the fault arises
Continue to Step 4Pressure not correct: obstructions in the 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
4COIL OPERATION AND SUPPLY CHECKAll OKProblems metOperation
2.0 JTSCheck the continuity/insulation of the supply circuit and coil operation; in particular, make sure that the coil operating signal is present See    See E5030 PETROL ENGINE ELECTRONIC MANAGEMENTContinue to Step 6Faulty wiringrenew the wiring See    See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT
wiring intact, no signalContinue to Step 6
5CHECK ON FUEL PRESSURE ON ROADAll OKProblems metOperation
3.2 V6Road test the vehicle and check the fuel supply pressure Op.    Op. 0510C10 FUEL SYSTEM - CHECK DELIVERY PRESSURE.
Make sure to reproduce the conditions in which the fault arises
Continue to Step 6Pressure not correct: obstructions in the 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
6CHECK ON CORRECT OPERATIONAll OKProblems metOperation
2.0 JTSCheck that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace engine management control unit Op. 1056F82
3.2 V6Check that the fault is no longer presentEnd of diagnosisFault persists: control unit faultyReplace engine management control unit Op. 1056B82