Toyota Sienna 2010 Owner's Manual page 328

3-4. Using the hands-free phone system (for cellular phone)
Steering wheel telephone switches
■
Microphone
■
332
Volume
The voice guidance volume
cannot be adjusted using
this button.
Hands-free phone system
off/ends a call/refuses a call
Hands-free phone system
on/starts a call
Press: Voice command sys-
tem on
Press and hold: Voice com-
mand system off