Toyota 2005 Sienna Owner's Manual page 352

To turn on: Push the switch.
The indicator comes on and the buzzer
will sound.
To turn off: Push the switch again.
In the following cases, the buzzer will
sound several times and the indicator
will stay on to indicate that the system
is not working properly.
When the temperature is extremely low.
D
When any of the sensors are malfunc-
D
tion.
344
05 SIENNA_U (L/O 0409)
If the indicator is continuously on, have
your Toyota dealer check the system.
If the indicator remains blinking but
you do not hear the buzzer sound,
clean the sensors with soft cloth.
Rear sensors
Rear corner sensors
2005 SIENNA from Sep. '04 Prod. (OM45431U)