12v battery suspected culprit for front door locks malfunction?

The 12v batteries in Toyota hybrids definitely last longer than the typical 3 years expected from a new car battery, but a 2012 with 140,000 miles could certainly be due for a new one. My 2012 is just under that mileage and I replaced the 12v last year. I don't know if a faulty 12v would cause that "check hybrid battery" message, although I know you're hoping it is . Have your battery checked for volts and cold cranking amps to see if it's up to snuff. If it's not, expect to pay close to $300.00 installed at a dealer. It will come with an 84 month warranty.

If that makes your error message disappear thank the hybrid gods. Replacing the hybrid battery could cost more than 10 times the 12v. You might want to look into the Mr. Prius app for testing the condition of the hybrid battery. The app itself is free. The Remaining Life Test module for it costs around 9 dollars.

 

The 12 V battery causing that is a LONG shot.
BUT.....it can be tested. And if it really IS 8 years old, replace it.
It can be a contributing factor in your other trouble indications.

Much more likely is that your lock actuators in the doors have failed.
That is a common problem.
Do they lock/unlock properly when you use the electric button on the door ? (not the manual rocker).

 

The car is old enough that both the hybrid and 12v batteries could be bad.

I might take the door locks as an extra sign that the 12v was failing, but really both batteries need to be properly tested.