Turn the ignition key OFF.

Disconnect the cable loom from the lambda sensor on the preconverter

In the engine bay junction unit, remove relay T6 (it is the first at the bottom in the middle row).

Connect a shunt cable with a fuse between across pin 87 of the base unit for relay T6 and the battery positive.

Measure the voltage between Pin 4 of the sensor and Earth, ensuring it is greater than 11 V.

See K040 LAMBDA SENSOR

Move on to Step 3

If faults are present, repair or if necessary replace the wiring between the junction unit and the lambda sensor

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

The test can be considered over

Replace the junction unit

Op. 5505A13 ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R.

Disconnect the shunt connection.

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

Turn the ignition key ON.

Measure the voltage between Pin 3 (wiring side) of the sensor and earth is less than 0.3 V.

See K040 LAMBDA SENSOR

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

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

Turn the ignition key OFF.

Check that the resistance between Pin 3 (wiring side) of the sensor and earth is greater than 500 kOhms

See K040 LAMBDA SENSOR

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

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

Measure the resistance between Pin 3 (wiring side) of the sensor and Pin 51 (wiring side) of the control unit is less than 5 Ohms

See K040 LAMBDA SENSOR

See M010 ENGINE MANAGEMENT ECU

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

See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT

Turn the ignition key OFF.

Check that the resistance between Pins 3 and 4 (wiring side) of the sensor are between 1 and 20 Ohms

See K040 LAMBDA SENSOR

Replace the Lambda sensor

Op. 1080B90 LAMBDA SENSOR - R.R.

Replace the engine management control unit

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