2007 ToyotaPrius engine • EG022-04 — 2001-’03 Prius. The MIL may come on and set a DTC P3130, and maybe also a DTC P3125, which are codes for a power problem or the Ready light not coming on. The fault may occur after the vehicle has been subjected to prolonged driving in heavy stop-and-go traffic, or when it has been driven at sustained high speeds during hot weather. The problem may be an overheated inverter/converter due to loss of coolant or coolant not circulating properly in the inverter/converter cooling system.
Because the inverter/converter is part of the high-voltage system, you do not want to touch anything until the high-voltage hybrid battery has been disconnected by pulling out the power service plug in the trunk. You then must wait at least five minutes for the high-voltage capacitors in the inverter/converter to discharge before proceeding with repairs to the cooling system or inverter/converter assembly. The bulletin covers how to drain, refill and bleed the cooling system, and the replacement of the inverter/converter assembly.