I own a 2012 Prius C and one day i couldn't unlock the car. The red light on my key fob blinks when i use it, but the doors still don't unlock. The only way to lock or unlock my car now is manually, the electronic lock switch on the doors don't work either. On the same day that this happened the ABS and Brake lights on the dashboard lit up for the first time. I've been reading around and seen that it might be the 12v battery, but I ran a diagnostic and it is working fine. I'm thinking it might be a fuse, or some messed up wiring, but im not sure.
There's a known problem with Prius C door lock systems... Yours sounds a bit different, but first step is to do a search on google with priuschat in the key words and do some reading up on the subject.
I've been searching for a few days and I can't find anything that exactly fits my situation. There are a lot of posts about the door lock actuator, but i don't think it's that. My doors won't even attempt to lock. I was hoping that someone on here has had the same issue as i do with the locks
I ran a diagnostic test on the car that checks the batteries health and it said it was running at 12 volts. And I dont see any other signs of a dying battery
The only other problem is the thing with the brakes I mentioned in the first post. Everything else is working fine
What are trouble codes? I dont know much about this stuff. I only started doing research once my car started acting up
I agree, time to revisit that 12v test. Not everyone realizes that the difference between success and failure is only about one volt, when doing the simplest kind of open circuit testing. A fresh, fully charged battery with no load (car completely off or battery disconnected) should read around 12.70V. A 12.00 volt reading would suggest a battery that was significantly discharged or degraded. How old is that battery? A 2012 would normally be working on its second battery by now, maybe even third.
Unfortunately the 2012 does not have jump points under the hood. But wonder if you can hook up jumper cables to the batt (correct +/- on the terminals, to avoid messing things up) and see if key fob works correctly then. And as pointed out already, if 12v is the original, then likely the culprit. Low/expired 12v starts giving funny dash lights and issues that can be easily remedied by changing it out.
I thought the 12v battery should read somewhere around 13.5 - 14 and change considering. If it is only reading 12, is that under a load? Have you disconnected the battery from the car (The negative terminal) and read the voltage across the terminals? Do you have a known, good 12v battery you can substitute in there or take a known, good, fully charged battery and a pair of jumper cables, attach it to the battery and see if your door locks operate. Even a lawn tractor battery should work for that.
There are a couple of questions here I need to address. The test I ran for the 12v was one that you could run from the prius itself. Here is a link to the video I watched that showed me how to do it. When i run this test it shows the battery at 12.0v. If I turn on the headlights, or roll down the window during the test the battery drops to around 11.3-11.7v and then goes back to 12v when I turn the headlights off, or when I stop rolling the windows. I thought that was ok, but judging from the comment above I might actually need a new battery. I dont know how old the battery is. I bought the car used about 3 years ago and I haven't had any issues with it until now. I also forgot to mention that the cruise control doesn't work anymore either. When I try it a message comes up that says "CHECK CRUISE CONTROL SYSTEM" Are there any other tests I can run on the battery to make sure that is definitely the issue?
hmmm, you have a dash that looks like that? not sure the 2012 "c" has that internal dash 12v battery check. When I had mine, I wasnt aware, although many things i could prob add to that list Although a Gen3 (2012) would not have it either. Do you know how to access the 12v battery? If so, you could check to see it there is a date code on it, or see if it is oem. Could also keep it accessible and then after say 12 hours could use multimeter to check the resting voltage....but this cannot be done after drivers side door is opened. Perhaps keeping the back door unlocked and then turning off interior lights and then accessing it that way after the 12 hours of resting.
The dash in my car doesn't look like that, but i was still able to access the same menu using the same method they did in the video. The only difference is that they say to hold the "Info" button in the video. My car doesn't have an "info" button. I held down the "Car" button and did everything else the same.
a dealer, or good hybrid shop has a tool called a code reader. it hooks up to the computer system at a port under the steering wheel. when you get trouble lights, you get trouble codes. the codes relate to a service manual trouble shooting tree which leads to problem diagnosis and repair. you can buy one for $25. on amazon (mini vci), but there is a learning curve, and you need a compatible laptop. or there are some phone apps which work pretty well, but not quite as detailed, so don't always lead to a solution. it all starts with a healthy 12v though, and that is tough to define when you get down around the level you're at. the computers need proper voltage to give correct codes. if you don't want to buy a new battery, you should at least try charging yours to see if it will hold at a higher voltage.
Thank you for the advice. I will definitely consider getting a code reader if it will help me. I am pretty inexperienced when it comes to repairing cars, especially hybrid cars. This is the first hybrid car I've owned. How do I charge the battery? Is it essentially like jumping a car, or do i have to buy a tool to do it?
There are youtubes showing howto change the 12volt on a 2012 prius c. Without knowing the codes that were set when the trouble started, none of us really knows much about what the problem is with the door locks. If you have an Auto Zone (auto parts store) near you and they are not too busy, they may plug there code reader into your car and show you what the codes are, sometimes even for no cost. Write the code(s) down and and post them here and we can help you figure out what the problem(s) are.
Theoretically, if it is the battery causing the problems, if i hook up a charger to the battery and attempt to lock/unlock the doors with the key fob, it should work. Is that correct?
