The vehicle is equipped with many electronic control units with a self-diagnosis function. When a diagnosis equipment (Examiner or other device) is connected to these control units, self-diagnosis data can be read (parameters, errors) or the available active diagnosis tests can be carried out.

All the diagnosis lines flow into the EOBD connector (European On Board Diagnosis) which conforms with Directive 98/69/EC (EURO 3) - ISO standard J1962 - located under the dashboard to the left of the Body Computer.

Via the same connector it is possible to diagnose all the nodes (control units) connected to the low speed B-CAN and the high-speed C-CAN dynamic control network.

  See E1050 CAN CONNECTION LINES 

There are also individual diagnosis K lines that control individual control units: on this version this involves the electronics for the gas discharge headlights.

In LPG versions, a special diagnosis connector next to the control unit allows the LPG control unit self-diagnosis data to be read.

The central diagnosis socket R010 receives a direct battery power supply at pin 16 from the line protected by fuse F36 of the Body Computer M001; pins 4 and 5 of R010 are earthed.

The Body Computer M001 - connector A - receives a direct power supply from the battery through the line protected by maxi fuse F01 of the engine compartment junction unit B001.

The Body Computer M001 receives an ignition-operated (INT) power supply at pin 11 of connector E, whilst pin 9 of connector E of M001 provides the Body Computer with a reference earth.

Pins 6 and 14 are connected to the C-CAN: this network controls and diagnoses the engine management control unit M010 and the ABS-VDC control unit M050, the yaw sensor K074 and the electric steering control unit M086.

  See E1050 CAN CONNECTION LINES 

Pins 1 and 9 are connected to the B-CAN: this network controls and diagnoses the instrument panel E050, the radio P020, the Bluetooth control unit M162, the airbag control unit M060, the parking sensor control unit M084, the TPMS control unit M047 and the climate control system control unit M070

  See E1050 CAN CONNECTION LINES 

Pin 12 is connected, via a dedicated K line, to the electronics in the light clusters F010 and F011 on the gas discharge version.

  See E3080 HEADLAMP AGLINMENT CORRECTOR 

In LPG versions, a special diagnosis connector R022 allows the self-diagnosis data from control unit M018 to be read, connecting to pins 10, 11, 38 and 39 of M018. This is then connected to the K line of connector R10, dedicated to the engine management - pin 7.