Precautions To Be Observed When Inspecting Or Servicing Engine Compartment
WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
The PRIUS automatically turns the engine ON and OFF when the ignition switch is set to the ON position provided that the READY light on the instrument panel is lit. Before inspecting or servicing the engine compartment, therefore, remove the ignition switch key.