Water pump and Overheating

Hello Prius friends.
I’m having issues with overheating and hope someone can assist with some ideas.

I have a 2012 Prius V.
During the summer car ran fine no issues.
In the summer I replaced radiator due to a a leak in radiator.
As soon as winter started i had no heat so then I decided to purge the cooling system and didn’t help. I’ve replaced water pump and thermostat and no I’m having problems with overheating.
Car heats up then in high speeds I get the high temperature light flashing. I have to slow down to make it go away.
* I pulled over last night and noticed the fans would come on and off when car was overheating. The strange thing is that the water pump would do the same thing. It wouldn’t stay running constantly, it would come on and off. I was able to hear the coolant flow on and off.
Does anyone know what controls the water pump to make it stay running constantly. These Prius’s have two temperature sensors I’m assuming one is for engine temperature and the other one is for HVAC.
Any input is greatly appreciated.

 

Thanks for your reply. But I get no codes just the flashing temperature red light.

 

Light (high temperature light) only flashes at high speed stepping on gas when engine running.

 

I will try that again. I’ll keep you posted. But my main concern still the on/off water pump. That seems to lead me to the major issue with this problem. I believe water pump should stay running constantly.

 

Hello everyone.
This past weekend I replaces both temperature sensors verified there were no obstructions and burped the cooling system. Looks like is fixed now crossing fingers. Took it for a drive and no hot engine light. Heat is also working fine. I hope when it got hot last few times It didn’t damage my head gasket.
Took about an hour to burp. Here is a video that I’d like to share. My car does have the bleed port. Also this is a swapped engine from a 2018 Prius. My car is a 2012 Prius V I swapped the engine back in June.