The steering wheel switches can be used to operate a connected cellular phone.
Operating a telephone using the steering wheel switches
On hook switch

Bluetooth® phone
message function
Bluetooth® phone
settingsIg power source circuit
Description
This is the main power source supplied to the air conditioning amplifier when
the ignition switch is on.
This power source is used for operating components, such as the air conditioning
amplifier and servo
motors.
Wiring diagram
Inspection procedure
Inspect fuse (ecu-i ...
License plate light assembly
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove back door center garnish (see page
ed-59)
...
On-vehicle inspection
Check ignition coil assembly and perform spark test
Notice:
in this section, the terms "cold" and "hot" refer to
the temperature of the coils. "Cold" means
approximately -10 to 50°c (14 to 122°f). "Hot" means
approximately 50 to 100°c (122 to 212 ...