05 Prius. I got this car cheap and can only afford cheap fixes. Check engine light has been on for a while. Code came out as P1121 - coolant flow control valve position sensor circuit stick. I haven't worried about it but recently my master warning light, VSC and one other light came on simultaneously and the car struggled accelerating. Code P0A80 - replace hybrid battery pack. It told me three cell blocks were weak. This is my first car I've worked on myself. I replaced three bad cells and reinstalled the battery pack. When I restarted the car the AC no longer worked, all but the check engine light disappeared but after three days the master warning light came back on. The report doesn't say any cells are weak and the car is driving fine but it still says I need to replace the battery pack. Does the coolant control valve have any affect on the hybrid battery pack?
Welcome to Prius Chat . Some questions: How many miles on your Prius? Did you condition the modules before entering them into the pack? What are you using to read the codes? Why not replace the 3 way valve as you know that is an issue? Good luck and keep us posted .
The Prius has 260k miles. I didn't condition the batteries but when I pulled them out again they are still holding a charge. I have been using BlueDriver OBD2 to read the codes. I haven't replaced the 3 way valve because it hasn't seemed to affect anything. And now with battery issue I'm sure I can even get $500 for the vehicle.. why put more money Into it?
The valve is something known that will begin to affect performance of the heating system once the warm weather goes away. The new modules holding a charge isn’t the issue, it’s the differences between those modules and the ones that pre-exist that is the cause for concern by the computers . What year are the modules you are inputting into the pack? If you want to sell it, I k ow a member here who’d probably be willing to take it off of your hands too. Good luck and keep us posted .
If your going to do the module swap route perhaps you should do some reading first Gen II Prius Individual Battery Module Replacement | PriusChat I might be interested if the price is right
