The temperature control unit of your Toyota vehicle has various bulbs that allow the control buttons and switches to be illuminated in the dark. If the bulbs burn out, you should try to replace them as soon as you can in order to be able to view the controls when driving at night. Most control units on modern Toyota vehicles are held in by several screws that are covered up by the central dash cover. Once those components are removed, the temperature control unit can be removed and the light can be replaced.
Turn the Toyota's engine off.
Use a slotted screwdriver to remove the clips from the central dashboard cover. Pry the cover off with the screwdriver.
Uninstall the four screws holding the temperature control unit in place to the Toyota vehicle with a Phillips screwdriver. There are two screws at the top corners and two screws below the knobs.
Pull the unit out of the vehicle and disconnect its electrical connector. Remove it from the vehicle.
Remove the faulty bulb from the rear of the temperature control unit. Simply pull the bulb out to remove it and install a replacement bulb by clicking it into place.
Reinstall the temperature control unit and reconnect its electrical connector. Reinstall the screws and reattach the central dashboard cover.
Check your vehicle's owner's manual for the exact bulb to use with your Toyota vehicle. Most Toyota vehicles use 194LL-type bulbs.