Sienna FWD V6-3.3L (3MZ-FE) (2006)
a. Measure the resistance of the seat heater switch when the switch is operated.
If the result is not as specified, replace the switch.
HINT: As the dial is being turned, the resistance changes gradually.
b. Push the seat heater switch ON and check that the seat heater switch indicator illuminates when the switch is operated.
If the result is not as specified, replace the switch.
c. Check the seat heater switch illumination.
If the result is not as specified, replace the seat heater switch or bulb.