The code C1242 comes up as an ABS power circuit problem but it's almost always related to inverter coolant pump. If your Gen1 won't READY up or catastrophically failed and the gas gauge is "dancing around" check the blue 15 amp fuse in position labeled AM2 under the hood (the fusebox near drivers headlamp). After you replace the fuse check flow in inverter coolant reservoir. If no flow you have a bad inverter coolant pump which blew the fuse then bricked the car. And if your Gen1 has not had the inverter coolant pump replaced in the last 100k miles I suggest you replace it as a preventative measure with a new one. (Just had another Gen1 towed in this morning because of this problem). These electric pumps are on whenever car is Ready, but they don't last forever and are critical to the operation of the car, that's why I recommend changing them before they break and leave you stranded.
Where is the pump and are there I'm looking for posts on flushing the coolant in the engine and the inverter in my 01 model but haven't found any with instructions. Are there any out there?
Heres' some info on the inverter pump: Inverter Coolant Leak - need help (Pics) | PriusChat Engine coolant is not that critical to change out, but there is a draincock at bottom of radiator drivers side and backside of engine block on right side. Use compressed air or shop vac in reverse to blow out the engine coolant if you really want to change it.
