Suzuki Nexa S-CROSS series 2015 Owner's Manual & Service Booklet page 175

(2)
(1) VOL PUSH POWER knob
(2) TUNE FOLDER PUSH SOUND knob
(3) MUTE button
(3)
(1)
64MS187
Press the VOL PUSH POWER knob (1).
The unit starts in the function mode it was
in when the power was turned off last.
Turn the VOL PUSH POWER knob (1).
Turning it clockwise increases the volume;
turning it counterclockwise decreases the
volume.
NOTE:
While driving, adjust the volume to an
extent that sound and/or noise coming
from outside the vehicle can be heard.