At service temperature, with the engine idling and all electrical appliances off, temperature reading should be between -10 and 80 °C.

The test can be considered over

Turn the ignition key OFF.

Disconnect the cable loom connector from the engine management control unit connector A.

Turn the ignition key ON.

Measure the voltage across control unit sensor Pin 13 (wiring side)

See M010 ENGINE MANAGEMENT ECU

and Earth, checking it is less than 0.3 V.

Move on to Step 4

Turn the ignition key OFF.

Measure the resistance across control unit sensor Pin 13 (wiring side)

See M010 ENGINE MANAGEMENT ECU

and Earth, checking it is greater than 500 kOhms

Disconnect the wiring harness connector from the fuel temperature sensor.

Measure the resistance across control unit sensor Pin 13 (wiring side)

See M010 ENGINE MANAGEMENT ECU

and sensor Pin 1 (wiring side)

See K101 FUEL TEMPERATURE AND WATER IN FUEL FILTER SENSOR

checking that it is less than 5 Ohm.

Repair or if necessary replace the electrical wiring between the engine control unit and the resistance

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

Measure the resistance across control unit sensor Pin 61 (wiring side)

See M010 ENGINE MANAGEMENT ECU

and sensor Pin 2 (wiring side)

See K101 FUEL TEMPERATURE AND WATER IN FUEL FILTER SENSOR

checking that it is less than 5 Ohm.

Repair or if necessary replace the electrical wiring between the engine control unit and the sensor

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

Replace the sensor

Op. 1060G30 WATER PRESENCE SENSOR IN FUEL FILTER - R.R.

and check the fault has disappeared

Repair the original resistance and replace the engine management control unit.

Op. 1060G80 DIESEL ELECTRONIC INJECTION CONTROL UNIT - R.R