Toyota Repair Problems? Ask a Mechanic for Answers ASAP
Hello and thank you for trusting us with your Toyota question, My name is XXXXX XXXXX I will be assisting you today.
Are you available to discuss your question at this time?
yes thank you very much
Hello! How are you doing today?
Hi AMD it's been a good day so far
Wonderful! If I may ask, how many miles or kilometers on your vehicle?
just around about 26000 km on the Prius 2012 that i'm driving now
OK I See. Just to verify, you mentioned that you leave your vehicle parked for 2-3 months without being started or anything?
just bought them at the end of last year
yep that's right
without being start - -"
OK. I am a hybrid certified technician and I specialize in Prius vehicles like yours. I will explain what I think is going on here then I will go on to explain what does the 12V battery does.
Very relieved to get some info from an expert thank you very much sir
First I agree that the 12v battery is the issue. The vehicle was not designed to be left for 2-3 months without being run, And the 12v battery in your prius is a known weak point. It's a very small battery that doesn't last a very long time and I will explain why it's so small. Typically in a situation like yours where you would leave the vehicle for a very long time, you either disconnect the battery or utilize a battery maintainer. A battery maintainer is basically a small device that plugs into the wall and then onto the battery that will keep a very small charge on the battery to keep it from dropping over time
the reason it drops over time is because even though everything is off in the vehicle at least one out of the 33 computers on board is awake and ready to detect the key and start the vehicle.
So it will drain a very small amount and over 2-3 months it will be enough to bring the battery voltage down enough to cause all kinds of abnormal issues
Making sense so far?
making very good sense so far sir
OK now let me talk about what that battery does.
The 12v battery has a very basic function in life in your car. when the hybrid system is OFF meaning the READY light is OFF it will power the interior electronics like the radio and lights. When you start the vehicle the 12v battery will power up the computers to start the hybrid system, the 12v battery function STOPS as soon as the READY light comes on and then the hybrid system will charge the small 12v battery from the high voltage battery. Does this make sense?
right, so when the car is started and ready to run, the 12V batter does not have any function to do with the car at all
That is correct. However let me point one thing out and this is something that comes from experience.
When you turn your prius on, the on board computer does a comprehensive check of all components and then if it sees any issues it will illuminate a warning light. When the 12v battery is low, common for the computer to act abnormally because of the low voltage.
So for example it could cause the car not to ready on. it also could cause the p malfunction.
Do you have any questions about the 12v battery before we talk about the brakes?
nope, because the reason i'm asking about the 12V battery is that, i'm wondering if it has anything to do with the stiff brake pedal
If I may ask, are there any warning lights in the dash once the vehicle is running and driving?
nope there are no warning lights once running and driving
when the car almost coming to a stop when pressed the break pedal
the p-malfunction alert comes on
with a beep sound, then disappear
OK I See. I see that you've listed your country as Thailand, Is your Prius purchased new in Thailand or is it an import from another country?
purchased new in thailand sir
OK, I am in the US so I wouldn't know how things are in your country so excuse me for asking, Was the vehicle purchased at a Toyota dealership?
yep it was purchased from the official toyota dealer
OK again things might be a bit different from my country and your country but the company is the same so the vehicle should still have it's manufacturer warranty in effect, Did you take the vehicle back to toyota's service center for an inspection?
yep i do check the car regularly with the dealer and warranty is still in effect
OK Regarding the p lock malfunction the dealership will need to run a health check to see if there are any codes present and follow up with diagnosis from there. It could still be a weak battery throwing the on board computer off but without an in-person inspection and an interaction with the on board computer of your vehicle it's really hard to tell exactly what is going on.
So what I suggest you do is this
First stop by your local dealership, have them test the 12v battery or it's called Auxiliary battery in Toyota terms.
If the battery fails the load test, have them replace it as it should still be under warranty.
Then have the dealer run a health check on the vehicle using their equipment and go from there.
if they come back to you and tell you everything checks out fine, then take a drive with one of their technicians and show them the issue with the p lock malfunction.
sometimes they need to be checking for issues while the p malfunction happens because other times when it disappears there will be no error codes in the computer.
Also consult the dealership for a suitable battery maintainer. basically explain to them that you could leave the vehicle for 2-3 months at a time and have them recommend a suitable maintainer for your vehicle to use and show you how to use it correctly so you can maintain the battery should you ever travel again so the battery wouldn't give you issues.
Did you have any other questions for me today?
just one more thing about the break
what might cause the stiff brake
OK Let's go into that with a bit more detail, When you say stiff, do you mean the pedal is hard to press? or do you mean the vehicle is hard to stop and you have to press it harder to make it stop?
and also when i try to break lightly, you know the hydraulic ish squish sound when you push the break on prius
sometimes it do the break by it self keeps squishing on and off rapidly
and the p-malfunction comes on
the vehicle is hard to stop and you have to press it harder to make it stop?
sorry, yes i mean the vehicle is hard to stop and you have to press it harder to make it stop
OK How many kms have you travelled since you came back from leaving the vehicle 2-3 months?
should be around 5000 kms
yep should be around 5000kms or a bit less
OK I think we might have a problem with the electronic controlled brakes. Typically any issue with the brakes will set multiple warning lights but just like the p malfunction issue, we will need a more in depth inspection of the issue. I can tell you this
From my experience with your vehicle there are no known issues that match the issues that you have. Whatever the vehicle will need it should be covered under warranty at the kms you have and the year so you shouldn't worry about costs.
However it's very important that you explain to the dealership exactly what you are experiencing and it would be best to take a technician for a drive and show them.
I doubt the brake problem is related to the 12v battery, but again without an in person inspection it's really hard for me to tell exactly what's going on
yep i'm quite clear now what to tell the technicians
that's about it thank you very much sir
You're welcome. A positive rating for my input would be greatly appreciated.
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