Does Code p1171 Exist?

I bought my Prius 1.5 years ago with 90k miles on it. When I bought it, it had the check engine light on, p1121 coolant control valve sticking, and the dealership said it would cost $500 to repair. It got me a discount on the car, but I did my research here and discovered that this is a common problem that doesn't have to be repaired--and turns out it actually only goes on for a couple days here and there in the summer when it's really hot.

So, my car recently passed 100k, and I made an appointment for a checkup at a place a friend recommended. Then earlier in the week, even though it isn't hot, my check engine light came on for about 36 hours but then turned off. When I dropped my car off this morning, I told the mechanic about the check engine light. He did the check/diagnostic and told me that the car was giving a code p1171, coolant transfer valve and temp sensor problem, and that they'd been struggling to diagnose and figure out how to repair it. He quoted me $679 and said he wasn't comfortable with me driving the car home, that I could destroy the engine. I was shocked, and my car seems fine, so I drove it home anyway.

I've been trying to read up on this code, but I can't find a single mention of it on the internet! Does anyone else know about this code or issues with this valve? Is it possible he's somehow mixing it up with that p1121 code? Or is this a ticking time bomb I need to take care of ASAP? I'm planning on getting the code read at O'Reilly's to confirm it and calling the dealership to ask about it, any other suggestions would be appreciated!

 

Thanks, Patrick!

Update: I called two local Toyota dealerships. They both confirmed p1171 isn't a valid code. One told me that whoever gave me that code "didn't know what they were talking about" and that if the check engine light went off on its own, then it wasn't a continuing problem.