| 0 | Preliminary checks | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
|---|
|  | The fuel system is highly sensitive. The work must be carried out with the greatest cleanliness and care. Any air in the system could damage the high pressure fuel pump. The vehicle must therefore never be driven with the fuel tank empty. |
Check that the tank contains the correct type of fuel. The fuel reserve should be more than 5 litres. Check that there are no leaks from the fuel system. Check the hoses and pipes connected to identify any obstructions, damage, etc. Check that the connectors and seals are correctly fitted. | Move on to Step 1 | 1.The tank contains irregular substances (petrol, other fluids) | 1.Clean the tank and refill it correctly |
| 2.There are less than 5 litres in the tank | 2.Top up the fuel level to more than 5 litres |
| 3.Fuel system leaking or not correctly sealed | 3.Renew the seal for the system. If necessary, replace the faulty components |
| 4.Pipes obstructed or damaged | 4.Renew the pipes. If necessary, replace the faulty components |
| 1 | High pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check that the diesel pressure parameter is correct as described in the test. See Test 1060OD INSPECTION OF THE HIGH PRESSURE FUEL CIRCUIT | Move on to Step 12 | Pressure not correct | Move on to Step 2 |
| 2 | Injector high pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check, as described in the test, that the diesel leaks from the injector recirculation connections are small (seepage) and roughly equal to one another. See Test 1060OC INJECTORS SEAL TEST | Move on to Step 3 | Significant leak from one injector | Replace the injector |
| 3 | Low return pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check, as described in the test, that the pressure in the return pipe to the tank is less than 1 bar See Test 1060OA CHECK ON RETURN LOW PRESSURE FUEL CIRCUIT | Move on to Step 4 | Pressure above the maximum limit: return pipe to the tank obstructed | Repair the pipe, if necessary, replace it |
| 4 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check, as described in the test, that the diesel pressure between the filter and the pressure pump is between 2 and 3 bar See Test 1060OB CHECK ON SUPPLY LOW PRESSURE FUEL CIRCUIT | Move on to Step 10 | Pressure below the minimum limit or above the maximum limit | Move on to Step 5 |
| 5 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Constrict the return pipe downstream of the valve and carry out the test once again with the pipe constricted checking that the pressure at the filter outlet remains below 2 bar See Test 1060OB CHECK ON SUPPLY LOW PRESSURE FUEL CIRCUIT | Move on to Step 6 | Pressure rises to 5 bar: pressure regulator valve on filter mounting incorrectly adjusted | Replace the valveOp. 1044B16 |
| 6 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check that the difference in pressure upstream and downstream of the filter is less than 1 bar | Move on to Step 7 | Difference in pressure more than 1 bar | Replace the fuel filter cartridgeOp. 1044B20 |
| 7 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check that the supply pump pressure at the filter inlet is more than 2.2 bar | Move on to Step 10 | Pressure below 2.2 bar | Move on to Step 8 |
| 8 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Measure the difference in pressure between the electric pump outlet and the filter inlet and check that it is less than 0.3 bar | Move on to Step 9 | Difference in pressure more than 0.3 bar | Replace the pipe |
| 9 | Low supply pressure check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Check, as described in the test, that the pump supply voltage is equal to 12 V and that the current uptake is between 2 and 10 A See Test 1040AA SUPPLY VOLTAGE AND ABSORPTION CURRENT CHECKS | Move on to Step 10 | 1.Voltage lower than 12 V | 1.Renew electrical wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT |
| 2.Current greater than 10 A: pump defective | 2.Replace the fuel pump Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R |
| 3.Current less than 2 A: pump obstructed | 3.Replace the fuel pump and clean the fuel tank Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R |
| 10 | Correct operation check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Replace the DRV high pressure regulation valve and check that the fault is no longer present. Op. 1060E50 PRESSURE REGULATOR ON PRESSURE PUMP - R.R. | End of diagnosis | The fault persists | Move on to Step 11 |
| 11 | Correct operation check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Replace the pressure pump and check that the fault is no longer present Op. 1060E10 DIESEL INJECTION PRESSURE PUMP - R.R. | End of diagnosis | The fault persists | Contact technical service for further information on the problem |
| 12 | Fuel pump relay active diganosis | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Carry out the active diagnosis of the fuel pump relay using the diagnostic equipment checking that the result is positive | Move on to Step 13 | The active diagnosis not successful | Carry out the test See Test 1040AB SUBMERGED FUEL PUMP CHECK |
| 13 | Pressure regulator replacement | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Replace the fuel pressure regulator and check that the problem disappears Op. 1060E50 PRESSURE REGULATOR ON PRESSURE PUMP - R.R. | Move on to Step 14 | The fault persists | Renew the pressure regulator and replace the flow valveOp. 1060E20 |
| 14 | Correct operation check | ALL OK | PROBLEMS ENCOUNTERED | ACTION |
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| Replace the engine management control unit and check that the fault is no longer present Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - .R | End of diagnosis | The fault persists | Contact technical service for further information on the problem |
