2010 Toyota Prius Owners Manual - Page 208

2-2. Instrument cluster Touch tracer display (if equipped) When the audio control switches, climate control switches, "DISP" switch or "TRIP" switch of the steering wheel are touched, the touch tracer display will appear in front of the gauges, with the touched switch highlighted to allow the driver to identify the switch that is being operated. The switch can then be operated by further presses. 182