Hi there, Love this forum. Have been here for a while. and I am back. 2010 prius. have changed new 12v battery in 2018 from authrized Toyota workshop. -10 Celsius degree, havent charged 12v battery for a while (more than 1 months). I use my car for short commute 3-5 per week. Today when I try to start the car, something wired happened: 1. the back left door could not be opened at the beginning. all other 3 doors can be opened. Thought it might be frozen weather? finally manage to open that door. and after a short drive (10 km), when I park the car and use fob to lock, the car just responses 'pip pip'. It does not lock... Now the car is at my garage, charing 12v battery... Not sure what should I do? 1. Pretty sure there is not another fob in the car that cause the lock issue. 2. time to change the 12v battery? 3. just give it a night and see the car tomorrow..
You might need a battery maintainer. The short drives aren’t enough to keep the battery charged, especially in cold weather . Check the fob battery too