The overflow tank next to the radiator? Only if it is broken. Your post really makes no sense. You left out some key information, like the problem you are trying to solve.
That looks like a gen 3 setup though. I think the OP is talking about a gen 2. That's got a plain coolant reserve bottle, and radiator cap on the radiator.
Our 2009 Prius had a code P1151 Coolant Storage Tank. The dealer recommended replacing the heat storage tank for $3500. The actual problem was not diagnosed (malfunctioning temperature sensor, 3-way valve problem, leaking tank, etc). I thought the price was excessive. I replaced the 3-way valve, but the check engine light has come on again after about 100 miles. Can this tank be bypassed? Can the problem actually be diagnosed? I read another post that other Prius models (for Europe?) did not have this coolant storage tank. Thanks for any advice.
Read this thread: SOLVED P1151 Coolant Heat Storage Tank | PriusChat That price is excessive. You should be able to pick up one of these tanks for very little at a junkyard, they hardly ever fail. Before doing that, be sure that all the air is bled out of the system. Watch these two videos for easy to follow instructions:
Yes the problem can be diagnosed, but it requires someone who has adequate tooling and understands how the system works. (and at times that's not the dealer - unfortunately). I don't know what to recommend. Not many owners have the skillset needed to learn diagnostics. What scantool do you have? Do you hear a (pump) hum for a few seconds after turning the car off, and right before the engine starts in the morning? Posted via the PriusChat mobile app.
