2005 Toyota Prius Owners Manual - Page 220

Coolant heat storage system CAUTION Coolant flow control valve Iridium −tipped spark plugs D The coolant in this tank is hot even if the engine and radiator are cold. 30p103 Electric water pump Coolant heat storage tank D For replacement of the coolant, contact your Toyota dealer. D Do not touch bolts painted in yellow. (9 pieces) D In case the bolts are loosened, there is a risk of hot coolant coming out from inside the tank. The coolant heat storage tank system stores hot coolant and feeds it via the electric water pump automatically to warm the engine as required. This system helps generate clean emissions. To confirm the coolant heat storage system check, the pump may operate automatically with the vehicle stopped (in the "IG−OFF" mode). Although the pump may operate and cause noise while the vehicle is stopped, this does not indicate a malfunction. D When this has any malfunction, the surface of this tank gets hot. To prevent burning yourself, do not touch the tank. Your engine is fitted with iridium−tipped spark plugs. NOTICE Use only iridium−tipped spark plugs and do not adjust gaps for your engine performance and smooth drivability. INFORMATION D In such cases as the time of engine starting and a short trip after the engine is stopped, the electric water pump will work for a moment, but this is no problem. D This is for the preparation for good emission. 210