See also:

Call volume
Call volume can be only be adjusted during a call. Use the buttons in the steering wheel keypad or the infotainment system’s VOL control. ...

Check coolant level
The cooling system must be filled with coolant and not leak to operate at maximum efficiency. Check the coolant level regularly. The level should be between the MAX and MIN marks on the expansio ...

Low battery voltage
If the battery voltage is too low, the parking brake cannot be applied or released. Connect an auxiliary battery if the battery voltage is too low, see page 114. ...