| STEP | CHECK TO BE PERFORMED | REMEDIAL ACTION IF THE CHECK IS NOT OK |
|---|
| 1 | Flow meter power supply checkDetach the connector attached to the flow meter -Insert disconnector AD 456 n° 1806590000 across the flow meter connector and the wiring connectorConnect the positive probe of an Examiner to pin 1 and the negative probe to earth.Turn the ignition key to the MAR position and check that the battery voltage is more than 11 Volts.Move on to Step 2 | Restore the continuity or, if necessary, replace the electrical wiring between the engine control unit and the flow meter See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT Replace the junction unitOp. 5505A13 |
| 2 | Flow meter earth checkConnect the Examiner test probes across pins 1 and 2 of the disconnectorCheck the voltage is greater than 11 V.Move on to Step 3 | Repair or, if necessary, replace the electrical wiring between the engine management control unit and the flow meter See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT Replace the engine management control unit Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - R.R |
| 3 | Air flow rate signal checkConnect the Examiner in voltmeter mode across pins 4 and 2 of the disconnectorSelect the following full scale deflection values on the Voltmeter: Voltage 20 Volts f.s.dTime base: 2 secsPress STARTWith the engine idling, check for the presence of an air flow signal as shown in the attached graph.The signal pattern is subordinate to the quantity of air coming into the flow meter. If the air flow is increased, the voltage amplitude does not change significantly but the frequency of the output signal increases | Repair or, if necessary, replace the electrical wiring between the engine management control unit and the flow meter See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT Check the seal of the flow meter hose, replace the flow meter if it is OK. Op. 1060G10 AIR FLOW METER - R.R. |
| 4 | Aspirated air temperature signal checkConnect the Examiner in voltmeter mode across pins 3 and 2 of the disconnectorWith the engine idlingPress the START button on the voltmeterCheck for the presence of an air temperature square-wave signal with a working voltage of 5V and a duty cycle oscillating between 10% (with min. air temperature) and 90% (with max. air temperature), as in the attached graph. | Replace the flow meter Op. 1060G10 AIR FLOW METER - R.R. |
