|  | CHECK TO BE PERFORMED | RESOLUTION IF THE CHECK IS NOT OK | 
|---|
| 1 | Check that the glow plugs operate correctly | Replace the faulty glow plugs    Op. 5520C10  HEATER PLUGS - R+R | 
| 2 | Press the START/STOP button and turn off the engine.Disconnect the wiring harness connector from the glow plug control unit    See M015  PLUG PREHEATING CONTROL UNIT  Measure the voltage between Pin 3 of control unit wiring side connector A and Earth, ensuring it is greater than 11 V.    See M015  PLUG PREHEATING CONTROL UNIT  Move on to Step 6 | Move on to Step 3 | 
| 3 | In the engine bay junction unti, remove fuse F11 from the block (third from the right in the lower row).    See B001  JUNCTION UNIT  Measure the voltage between the fuse input contact and earth, checking it is less than 11 V | Repair or if necessary replace the electrical wiring between the junction unit in the engine compartment and the glow plug control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 4 | Restore the connections or, if necessary, replace the junction unit in the engine compartment    Op. 5505A13  ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R. The test may be considered completed |  | 
| 5 | Measure the voltage between Pins 1 and 3 of control unit wiring side connector A and Earth, ensuring it is greater than 11 V.    See M015  PLUG PREHEATING CONTROL UNIT | Restore the earth connection of the glow plug control unit or if necessary replace the electrical wiring    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 6 | Press the START/STOP button.Measure the voltage between Pin 1 of control unit wiring side connector A and Earth, ensuring it is greater than 11 V.    See M015  PLUG PREHEATING CONTROL UNIT | Repair or if necessary replace the electrical wiring between the junction unit in the engine compartment and the glow plug control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 7 | Select the following control unit at the diagnostic equipment: EDC16C39 Diesel electronic injection control unit.Carry out the active diagnosis for the preheating relay, checking that the result is positive.Move on to Step 10 | Move on to Step 9 | 
| 8 | If faults are present, repair or if necessary replace the electrical wiring between the glow plug preheating and the engine control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT  The test can be considered over | Replace the engine management control unit    Op. 1060G80  DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R | 
| 9 | Connect a shunt cable with fuse between pin 1 of control unit connector A and earth.    See M015  PLUG PREHEATING CONTROL UNIT  Carry out active diagnosis of the preheating relay to check whether it is successful or not | Move on to Step 8 | 
| 10 | Press the START/STOP button.Disconnect the shunt connection.Disconnect the wiring harness connector from engine control unit connector A    See M010  ENGINE MANAGEMENT ECU  Press the START/STOP button.Measure the voltage between Pin 2 of control unit wiring side connector A and Earth, ensuring it is less than 0.3 V.    See M015  PLUG PREHEATING CONTROL UNIT | Repair or if necessary replace the electrical wiring between the engine compartment control unit and the glow plug control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 11 | Press the START/STOP button.Measure the resistance between Pin 2 of control unit wiring side connector A and Earth, ensuring it is greater than 500 V.    See M015  PLUG PREHEATING CONTROL UNIT | Repair or if necessary replace the electrical wiring between the engine compartment control unit and the glow plug control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 12 | Measure the resistance between Pin 2 of control unit connector A and Pin 93 of control unit connector A to ensure it is less than 5 Ohms    See M015  PLUG PREHEATING CONTROL UNIT      See M010  ENGINE MANAGEMENT ECU | Repair or if necessary replace the electrical wiring between the engine compartment control unit and the glow plug control unit.    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 13 | Disconnect the wiring harness connector from the first two glow plugs A and B.    See A040  HEATER PLUGS   Turn the ignition key ON.Measure the voltage between Pins 1 and 2 of the control unit and Earth, ensuring it is less than 0.3 V.    See M015  PLUG PREHEATING CONTROL UNIT | Repair or if necessary replace the electrical wiring between the glow plug control unt and the glow plugs    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 14 | Press the START/STOP button.Measure the resistance between Pins 1 and 2 of the control unit and glow plugs A and B, ensuring it is less than 5 Ohms.    See M015  PLUG PREHEATING CONTROL UNIT      See A040  HEATER PLUGS | Repair or if necessary replace the electrical wiring between the glow plug control unt and the glow plugs    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 16 | Replace the glow plug control unti and ensure the fault disappears.    Op. 5520C20  HEATER PLUGS CONTROL UNIT - R.R  The test can be considered over | Move on to Step 16 | 
| 16 | Repair the original glow plug control unit.Disconnect the wiring harness connector from the other two glow plugs C and D.    See A040  HEATER PLUGS   Press the START/STOP button.Measure the voltage between Pins 3 and 4 of the control unit and Earth, ensuring it is less than 0.3 V.    See M015  PLUG PREHEATING CONTROL UNIT | Repair or if necessary replace the electrical wiring between the glow plug control unt and the glow plugs    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 17 | Turn the ignition key OFF.Measure the resistance between Pins 3 and 4 of the control unit and glow plugs C and D, ensuring it is less than 5 Ohms.    See M015  PLUG PREHEATING CONTROL UNIT      See A040  HEATER PLUGS | Repair or if necessary replace the electrical wiring between the glow plug control unt and the glow plugs    See E5050  DIESEL ENGINES ELECTRONIC MANAGEMENT | 
| 18 | Replace the engine management control unit    Op. 1060G80  DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R |  |