2007 with 170k miles on it. All lights are on- red triangle of death, car with exclamation point on screen, VCS...etc. We checked codes and it gave us NO code readings... We checked the 12v and it was throwing a 5...we replaced it today. Drove a couple miles and lights came back on. Oil changed and all fluids are full.....help?! I'm trying to make sure everything is checked off BEFORE resorting to a new hybrid battery.
There is a possibility that computer scanner your friend used doesn't read Toyota Hybrid codes. You might need to find a Mini-VCI cable (which uses a windows type computer or emulator) and then run a copy of Techstream. The other option is a small ELM OBD2 bluetooth adapter that plugs into your Prius, then run something like Torque. There are plenty of threads here that talk about sourcing and using both of the above. The techstream approach is more thorough.