Toyota 2008 Prius Quick Reference Manual page 301

Status display
You can check such indicators as signal strength and battery charge
on the "Telephone" screen.
Indicators
Connection status
Battery charge
Call area
Signal strength
PRIUS_U_(L/O_0802)
Connection status
Battery charge
1 2 3 4
Call area
Signal strength
ITY34P003
Blue: Good
Yellow: Bad
: Not connected
: Full
: Low
"Rm": Roaming area
"Hm": Home area
: Good
: Bad
: Not connected
3-4. Using the hands-free system
Conditions
3
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