You can reset the codes on your Toyota in your home garage, saving yourself a trip to the mechanic or dealership. Toyotas come standard with an On-Board Diagnostics computer that receives and stores trouble codes sent from sensors positioned throughout the vehicle. When it receives a trouble code, it illuminates a warning or service light on the vehicle's instrument panel. You may need to have the car repaired or serviced by a qualified mechanic before resetting the code or the lights will turn themselves back on.
Locate the vehicle's OBD-II port on the driver's side dashboard near the fuse panel cover. The port should be the same size and shape as the connector end of your OBD-II reader. An OBD-II reader is a small, hand-held, computerised device that you can purchase from your local auto parts store.
Plug the reader into the port. Put the key into the ignition and turn it to the "II" position, but do not start the engine. Wait while the vehicle's electrical system powers on the OBD-II reader.
Find the "Delete Codes" command on the reader, or a similar command. Commands vary between readers, depending on its manufacturer. Select the command and wait for the "Command Sent" message to display or until the main menu reappears on the device.
Unplug the reader and start the vehicle's engine. Verify that all warning and service lights have shut off on the instrument cluster. The computer has been reset and the codes have cleared.
Most auto parts retailers will loan you OBD-II readers free of charge for the purpose of resetting the codes.