Issue starting when it is cold

Chad, congratulations! Your 2010 Prius is the only one that I've ever heard of that does this. Let's check! Anyone else?

 

The only time you should spend on this is the time it takes to get it to the dealer. These thing don't heal themselves.

 

Probably not getting to Ready mode which prevents you from shifting or the gas engine from starting. First guess would be a low 12v battery effected strongly by the low temps.

 

I agree that a good guess would be your 12v battery.
I also agree that your best move is to simply have it diagnosed at the dealership. You should still be under warranty?

 

What weight oil are you using?

 

If you actually read the post, the problem is not with engine starting, but rather getting the Ready light. My guess is 12V battery, too.

 

I had a similar issue this morning. I went out to start my Prius and it made the most horrible sound like it did not want to start. Then it was ticking and knocking really loudly for about 10 min.....until it warmed up, I'm guessing. It is 2 degrees outside and only 5 degrees in my garage. So, that may have something to do with it. Is there some way to plug the car in to keep the engine warm?

 

Another possibility is the brake switch is not making. Check your brake light reflections to make sure the brake switch is working.

 

I vote low 12V. Happened to me twice, when I knew I ran down the 12V prior.
Did I drain my aux battery too low? | PriusChat

 

There is a Toyota Service Bulletin regarding cold soak knocks (which is what it sounds like you are experiencing). Some people have noted this after the car has sat in a cold environment for awhile.

Could you enlighten us on what happened previously to the knocking you heard. Specifically, what was done with the car prior to shutting down before you started the car? For example, was the car moved from the driveway to the front of the house, the gas engine came on and ran for 2 seconds before being shut down. Then, the next day, you came out and started it and the engine started knocking (like a small hammer hitting inside the engine compartment a few to several times per second)?

 

Chad O - I had a similar problem to my car and it was the 12 volt battery. Next time it happens, check to see if you still have the "orange light" on the power button and see if the word "READY" is appearing on your dash. If you have a volt meter, take a measurement on the battery terminals (it's in the right rear of the car accessible from the hatch area).

If your 12 volt battery has had any discharges (leaving a dome light on all night, for example) it greatly shortens the life of these small batteries. I replaced my battery with an OPTIMA battery and this problem went away. The Optima battery is a bit more expensive that the OEM battery, but is supposed to be a lot more rugged.

My OEM battery lasted about 9 months before problems manifested. I replaced it after 18 months. Likely the car was in a dealership where people were in and out of it and wore down the 12 volt battery.

 

Yikes, what kind of a garage is that! Must live in Alaska?

 

yes, you can add an engine block heater that plugs in at night. see your dealer or qualified mechanic. you can also do it yourself if you are so inclined and have a place to work that is above 5 degrees.

 

Yesterday my Prius didn't start after I got in.
I couldn't lock the doors anymore after I got out.
I called Toyota Assistance and they jumpstarted the car and I drove straight away to the dealer.
It was supposed to be serviced today but I brought it in one day early.
It's still there.
The car has only 6K mi on it and I only have it for a week.
Temperatures were around freezing point ( 0 degr. C, 32 degr. F)

 

Hopefully they will find out what the issue is. I'm sorry that a week old car is giving you issues, but hopefully it is something that is easy to remedy.