Issues when starting up my 2010 Toyota Prius

Hello there, I'm new to this forum but I've been an on and off reader for quite some time. Anyways, I own a 2010 Toyota Prius (Version 1 I believe) and lately for the past few weeks, my Prius has been having start up issues. When I step on the brake pedal, I go to press the Power button, and my display has different issues. Sometimes, all the warning lights are displayed and there is no number next to the mph (it usually has the number 0 mph if the car starts up normally) and the vehicle is not able to drive. Other times the right side of the display is missing (where you can usually see a picture of the Prius or the graphs, etc) but when the right display is missing, it is still able to drive.

I brought my car into a Toyota dealership a few weeks ago and they, according to the service receipt, "had installed a scan tool to check the computer form codes and they found a Code U0155 was stored and the tested for cause and found a loss of communication to smart key ECU. They then cleared the code and said communication was restored and car now starts normally. If condition reoccurs, smart key computer will need replacement." Anyways, after I paid for that service, I got into my Prius and found the right side of the display missing issue still came up again while still at the dealership. I spoke to the manager and the technician and the technician brought a computer and plugged it into something underneath the steering wheel and I think he scanned the car again for any codes and didn't find anything and he even kindly issued me a refund. Anyways, he said to drive it for a while to see if the right display would come back up again and if it didn't, to bring it back to the dealership. The right display did come back up again after a few hours.

Everything was alright for a week and a half, no issues when starting the car up again. But the issues came up again today. When I first stepped on the brake pedal, all the warning lights came on, no number zero next to the mph and car was not able to drive. So I turned it off and tried it again a few more times, and on like the third or fourth time, it started up normally again. A little after, the right side of the display even went missing again but I turned it off and turned it back on and it started up normally and the right side of the display came back on again.

I don't know if this is relevant or not but this issue also seems to happen when the car is not driven for a few days. It usually happens on a Monday and the car is not driven during the weekends so I don't know if that is relevant or not but just something, I've noticed.

So anyways, I'm really perplexed, I'm not sure what is going on. I really hope it's not the smart key computer that needs to be replaced because according to the manager at the dealership, it would cost over a thousand dollars to replace it, which is a lot of money. Has anybody ever had this issue before? Is it really the smart key computer? Could it be the battery? Although at first, I thought it was the battery in the vehicle but the people at the dealership said it wasn't so I'm confused. Could it be the brakes? Because I do know that my brakes need to be placed soon according to the Toyota technician when I did my last every 5000 mile checkup. Or is it something completely different? Maybe something the people at the dealership missed?

I should have taken some pictures of the display, but I forgot to, but if the problem comes back, I'll take some pictures to further show the issues.

But please any help would be greatly appreciated. Thank you.

 

Is there a way for me to test the 12V battery myself to see if it is good or bad (I have a 2010 Prius Version 1 I believe)? Or do I need to bring the car in to a dealership and have them do it for me?

 

Besides the battery, is it possible the dealership is right about the smart key computer or ECU needing to be replaced? Has anybody even ever heard of the smart key computer/ECU? I tried to google it and eBay has several of them and they average about $100 and they're all used but the dealership estimates it'll cost me about $1000, which includes labor I think and I suppose the smart key computer would be new, but that still is a lot of money. But obviously, I really hope it is not the smart key computer that needs to be replaced but if it is, then, obviously, I need to get it fixed but I don't want to pay an obscene amount of money. And I'm not saying the dealership is cheating me or anything like that but since I'm not very knowledgable about the ins and outs of the Prius, I just want make sure I'm not being haggled because if it is something as simple as the battery being replaced, then great but if it is really the smart key computer/ECU needing to be replaced, then I expect to get the best price for it and most importantly, that it fixes the start up issues.

Please if anybody has any ideas or insight, please, I'd very much appreciate it.

 

I am the original owner. I bought the car new (2010 Toyota Prius Version 1) and I've had it over 7 years now. The car has never replaced the battery, at least to my knowledge. The car has about 40,000 miles on her.

I guess I will definitely check if the 12V battery needs to be replaced. But does anyone know besides buying the digital volt meter, are there any places where someone can check it for you, preferably free of charge (I know, I'm cheap lol)? I checked with Auto Zone but the guy said they don't touch hybrids. I know I can go back to the dealership but last time, the guy there said with hybrids, it's a lot more complicated to check if the battery is good or bad since underneath the hood, it is way too complicated to check it, compared to other non hybrid cars. He said he couldn't check it on the spot, the car would have to stay there and someone would have to do it but I'm not even sure if they even did check the battery because according to the service receipt, all they did was "installed a scan tool to check the computer form codes and they found a Code U0155 was stored and the tested for cause and found a loss of communication to smart key ECU. They then cleared the code and said communication was restored and car now starts normally. If condition reoccurs, smart key computer will need replacement."

But the guy at the dealership saying that hybrids are a bit complicated in checking the battery seems weird since a lot of people on this forum seem to be able to check their battery themselves, so I really don't understand why it would be so complicated for someone at the dealership to do it. I guess I can try it myself once I buy the digital volt meter but I'm pretty sure once I pop the hood, I'm still going to be confused as to where the battery is and how to check it.

Any suggestions?

Also, thanks again to everybody who has helped me out, really do appreciate it.