This unit describes the performance outcomes required to depower and reinitialise hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). It involves ensuring that the vehicle high voltage (HV) rechargeable energy storage system (RESS) is isolated before commencing any service or repair work. It also involves calibrating vehicle systems that may need resetting once the energy storage system is reinitialised. Importance is placed in the unit on applying RESS and separated extra low voltage (SELV) electrical safety procedures.