2013 Toyota Highlander Owners Manual - Page 180
2013 Toyota Highlander Manual
Page 180 highlights
2-2. Instrument cluster *3: These lights turn on when the engine switch is turned to the "ON" position (vehicles without smart key system) or the "POWER" switch is turned to ON mode (vehicles with smart key system) to indicate that a system check is being performed. They will turn off after the hybrid system is started, or after a few seconds. There may be a malfunction in a system if a light does not come on, or if the lights do not turn off. Have the vehicle inspected by your Toyota dealer for details. *4: The light flashes to indicate that the system is operating.