Additional heater control unit M075 receives power respectively:- at pin 1, via a direct line from the battery (+30), protected by fuse F23, from pin 32 connector A of engine compartment junction unit B001;- at pin 7, via an ignition-operated line (INT) protected by fuse F35, from pin 17 connector A of engine compartment junction unit B002;When climate control unit M070 sends a command from pin 17 connector A to pin 6 of additional heater control unti M075, this control unit supplies teh pump of additonal heater N044 via pin 4 and simultaneously activates the burner to heat the engine coolant to the required temperature.Additional heater pump N044 is connected to left rear earth C030 through inertia switch I050.The additional heater control unit M075 supplies, via pin 5, its own diagnostic signal used for the continuous monitoring of the entire device. See E8010 DIAGNOSTIC MULTIPLE CONNECTOR