Lexus 2014 LX570 Owner's Manual page 614

3-5. Using the hands-free system (for cellular phone)
Status display
You can check indicators such as signal strength and battery charge on
the "Phone" screen.
Indicators
Connection status
Battery charge
Call area
Signal strength
614
LX570_OM_OM60L21U_(U)
Connection status
Battery charge
Call area
Signal strength
Conditions
Good
Full
"Rm": Roaming area
Excellent
No
connection
Empty
Poor