The car is fitted with numerous electronic control units that perform a self-diagnostic function.When a diagnostic tester (Examiner or other device) is connected to these control units, self-diagnosis data can be read (parameters, errors) or the available active diagnostic tests can be carried out.As set out in the CEE EURO 3 regulations (in accordance with Directive 98/69/CE - ISO standard J1962 -) and CEE EURO 4 (in force since 01-01-2005) in addition to becoming more stringent about emissions, it is compulsory to install the EOBD (European On Board Diagnosis) in the vehicle in the Body Computer (connector C).The same connector is responsible for connecting nodes (control units) connected to the low transmission speed B-CAN network, while control units, while control units connected to the C-CAN network are tested by means of a specific K line.The following are checked via the B-CAN line:- junction unit under the dashboard;- instrument panel;- door control units;- radio controls on the steering wheel;- built-in radio-telephone-navigator unit;- boot comparment control unit;- seat position control unit;- (automatic) climate control sytem control unit;- Air Bag control unit;- parking sensor control unit;- steering lock control unit;- T.E.G. Reader.For more details, See E1050 CAN CONNECTION LINESThe following are monitored via individual diagnostic K lines:- engine management control unit (and automatic transmission control unit, if present)- ABS/ESP control unit;- electric steering control unit;- tyre pressure control unit;- headlamps electronic control unit (xenon gas discharge headlamps version);- additional heater control unit (JTD versions).