Won't start after replacing coolant control valve

I just attempted to replace the coolant control flow valve myself. It's all more difficult than ot looks and I lost more coolant than I expected, but I thought it went ok. But now it won't start. Can't get the car into maintenance mode to run the engine and circulate the coolant and bleed the air out. All the dash lights come on but the actually-on with the speedometer number won't work.

Anybody know what might have gone wrong? Any reason it might be in the failsafe mode?

Thanks

 

1. Ill check the battery tomorrow; thanks that's a good idea. I had it disconnected while I was working on it though, so I think that means there's less of a chance I drained it?

2. I definitely plugged in the connector. Triple checked it bc I didn't get as satisfying of a click as I wanted. One thing I'm worried about is if it got dirty/ got some coolant on it while I was installing the new one. Do you know if the connector is vulnerable to that?

3. I think so! But of course I keep going over it in my head to see if forgot about anything

 

I do have a code reader thing. It wasn't showing any codes.

Update: I took the hybrid battery safety out and in again, to make sure it was in correctly. I think I didn't have it pushed down all the way. Still, it didnt work the first time I tried after fixing that, but it did the second time.

 

That sounds like exactly what I need. Do you have a recommendation for a good code reader for Priuses? Thanks everyone!