You can reset the check engine light in your Toyota using an On-Board Diagnostics II scanner tool. When the light appears on your dashboard, have a mechanic look at your vehicle and fix any problems. The light can then be reset and turned off. Some people just disconnect the battery, but this will wipe out and reset the memory of other critical functions in your On-Board Diagnostics computer.
Look to the right side of the hood release handle on the driver's side of the Toyota and find a port. Plug the OBD II scanner tool into this port and turn the key in the ignition to the "II" position.
Press the scroll buttons on the scanner to go through the items on the menu. Find a command that says "Erase," and then press it.
Watch for the main menu to appear, or wait until you receive a scanner message reading "Command Sent." Unplug the OBD II scanner tool and turn on the engine. Inspect the dashboard to determine if the check engine light is off.