Toyota Yaris Owner's Manual page 348

348
7-3. Do-it-yourself maintenance
To equalize tire wear and help extend tire life, Toyota recommends
that tire rotation is carried out approximately every 10000 km (6000
miles).
Tire pressure warning system (if equipped)
Your vehicle is equipped with a tire pressure warning system that uses
tire pressure warning valves and transmitters to detect low tire infla-
tion pressure before serious problems arise.
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. (P. 408)
Installing tire pressure warning valves and transmitters (vehicles
with a tire pressure warning system)
When replacing tires or wheels, tire pressure warning valves and
transmitters must also be installed.
When new tire pressure warning valves and transmitters are installed,
new ID codes must be registered in the tire pressure warning com-
puter and the tire pressure warning system must be initialized. Have
tire pressure warning valve and transmitter ID codes registered by
any authorized Toyota dealer or repairer, or another duly qualified and
equipped professional. (P. 350)
Initializing the tire pressure warning system (vehicles with a tire
pressure warning system)

The tire pressure warning system must be initialized in the fol-
lowing circumstances:
 When rotating front and rear tires which have different tire infla-
tion pressures
 When the tire inflation pressure is changed such as when chang-
ing traveling speed
 When changing the tire size
When the tire pressure warning system is initialized, the current tire
inflation pressure is set as the benchmark pressure.