184000413 - D02 ENGINE NOT RUNNING SMOOTHLY / (LOSING POWER)
Under conditions of constant load and speed, there are intermittent decreases in performance, even prolonged| Results of the tests | ||||||
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation | ||
|---|---|---|---|---|---|---|
Check, in order:
| Continue to Step 1 | Fuel leaks | Restore the correct seal for the pipes, if necessary, replace them | |||
| Fault in air intake circuit | Repair the air intake circuit | |||||
| Obstruction in the exhaust system | Replace the damaged system component | |||||
| Water in diesel filter | Clean the tank and replace the filter | |||||
| 1 | CHECK WITH DIAGNOSTIC EQUIPMENT | All OK | Problems met | Operation | ||
| Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket Check:
| Continue to Step 2 | An error is detected in the control unit | Continue following the instructions for the diagnostic equipment | |||
| unreliable parameters | Continue following the instructions for the diagnostic equipment | |||||
| 2 | ROAD TEST WITH DIAGNOSTIC EQUIPMENT | All OK | Problems met | Operation | ||
Road test the vehicle keeping the diagnostic instrument connected.
Check:
| Continue to Step 3 | Errors suddenly occur in the control unit | Continue following the instructions for the diagnostic equipment | |||
| Parameters off scale | Continue following the instructions for the diagnostic equipment | |||||
| 3 | CHECK ON BRAKE PEDAL SWITCH | All OK | Problems met | Operation | ||
| Check that the pedal switch is working properly See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT | Continue to Step 4 | Brake pedal does not return | Eliminate the cause of the sticking | |||
| Switch faulty | Replace the switch | |||||
| Wiring short-circuit (intermittent) | Restore connection See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT | |||||
| 4 | HIGH PRESSURE CHECK | All OK | Problems met | Operation | ||
| Connect the diagnostic equipment to the diagnostic socket.Check as described in the test See Test 1060D Check high pressure fuel circuit that the diesel pressure parameter is correct. | Continue to Step 12 | Pressure too high | Continue to Step 5 | |||
| Pressure too low | Replace the pressure regulator Op. 1060E50 then continueContinue to Step 5 | |||||
| 5 | CHECK ON RETURN LOW PRESSURE | All OK | Problems met | Operation | ||
| Check as described in the test See Test 1060A Low return fuel pressure circuit check that the pressure in the return pipe to the tank is under 1 bar | Continue to Step 6 | Pressure above maximum limit: return pipe to tank blocked | Repair the pipe; if necessary replace it. | |||
| 6 | LOW SUPPLY PRESSURE CHECK | All OK | Problems met | Operation | ||
| Check as described in the See Test 1060B Low fuel pressure supply circuit check that the diesel pressure between the filter and pressure pump is between 2 and 3 bar | Continue to Step 12 | Pressure below minimum limit or above maximum limit | Continue to Step 7 | |||
| 7 | LOW SUPPLY PRESSURE CHECK | All OK | Problems met | Operation | ||
| Close the return pipe downstream of the low pressure regulator valve, located in the fuel filter cover, using the special tool and carry out the test See Test 1060B Low fuel pressure supply circuit check again with the pipe closed, checking that the filter outlet pressure remains below 2 bar. | Continue to Step 8 | Pressure rises to 5 bar: blocked pressure regulation valve on filter support | Replace the diesel filter cover | |||
| 8 | LOW SUPPLY PRESSURE CHECK | All OK | Problems met | Operation | ||
| Check that the difference in pressure upstream and downstream of the filter is less than 1 bar | Continue to Step 9 | Difference in pressure greater than 1 bar | Replace the diesel filter cartridge | |||
| 9 | LOW SUPPLY PRESSUR CHECK | All OK | Problems met | Operation | ||
| Check that the supply pump pressure at the filter inlet is over 2.2 bar | Continue to Step 12 | Pressure below 2 bar | Continue to Step 10 | |||
| 10 | LOW SUPPLY PRESSURE CHECK | All OK | Problems met | Operation | ||
| Measure the difference in pressure between electric pump outlet and filter inlet, checking that it is less than 0.3 bar | Continue to Step 11 | Difference in pressure greater than 0.3 bar | Replace the pipe | |||
| 11 | LOW SUPPLY PRESSURE CHECK | All OK | Problems met | Operation | ||
| Check as described in the test See Test 1040AA Check supply voltage' and absorption current' that the pump's supply voltage is 12V and that the absorbed current is between 2 and 10 amps. | Continue to Step 12 | Voltage < 12 V | Check electric wiring See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT | |||
| Current > 10 Amp: pump defective | Replace the fuel pump assembly Op. 1040A70 | |||||
| Current < 2 Amp.: pump blocked | Replace the fuel pump assembly Op. 1040A70 and clean the fuel tank | |||||
| 12 | CHECK ON CORRECT OPERATION | All OK | Problems met | Operation | ||
| Check that the fault is no longer present | End of diagnosis | The fault persists | Search for the fault starting from another symptom | |||
