The applied positions of the engine start pushbutton switch (S10) are read in and evaluated by the MR/PLD control unit.
Operating the engine start pushbutton switch (S10) has different effects, depending on whether the engine is running or not:
Operating the engine start pushbutton switch (S10) with the engine stopped:
the engine start pushbutton switch (S10) can be used to start the engine when the cab is tilted.
Operating the engine start pushbutton switch (S10) and engine stop pushbutton switch (S11) at the same time: this is done in service operations to crank the engine without starting, by interrupting the actuation of the solenoid valves in the unit pumps.
-----------------------------------------------------------------------------------------
A safety feature of the software in the MR/PLD control unit and FR control unit prevents the engine being started if a gear is engaged (starter protection function), or the starter being actuated if the engine is already running (starter locking).
-----------------------------------------------------------------------------------------
Effects of operating the engine start pushbutton switch (S10) when the engine is running:
If the engine start pushbutton switch (S10) is operated with the engine running, the MR/PLD control unit increases the idle speed continuously until the engine reaches limit speed or until the engine start pushbutton switch (S10) is released again. Once the engine start pushbutton switch (S10) is released, the engine control (MR) immediately reduces the idle speed again.
Since the MR/PLD control unit detects that the engine is running, it prevents the starter from being actuated again (starter locking).