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Issues when starting up my 2010 Toyota Prius

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Prius0722, Nov 14, 2016.

  1. Prius0722

    Prius0722 New Member

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    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.
     
  2. drysider

    drysider Active Member

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    The first thing to suspect is the 12v battery. If it is original, change it. I changed mine after 4 years even though it was working fine.
     
    bisco likes this.
  3. Kramah313

    Kramah313 Active Member

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    My guess is 12v battery also. It will discharge when not driven and charged by the main battery and make the problem worse. It doesn't start the vehicle like in a normal car so you can miss the warning signs a regular car would give (dragging starter, etc). Instead the computers probably will exhibit strange behavior when they get less power than they need.
     
  4. Prius0722

    Prius0722 New Member

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    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?
     
    #4 Prius0722, Nov 15, 2016
    Last edited: Nov 15, 2016
  5. bisco

    bisco cookie crumbler

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    yes. buy a digital volt meter. (amazon $10.) in the morning before starting the car, test the battery at the jump point under the hood. should be around 12.5 or so. i like to pop the hood in the evening, so i don't have to open the drivers door, which sets off the electronics and puts a load on the battery.
     
  6. Prius0722

    Prius0722 New Member

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    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.
     
  7. orlywon

    orlywon Member

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    My guess is that your 12v battery is so low that it doesn't have enough power to communicate with your smart key.
    I had all sort of strange errors when my 12v battery was dying (car would not go in Ready mode, display would turn off, then on, etc)
    Test your 12v battery first, if it's below 12.5V, it's probably time to replace it, especially If you never did.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    The dealership should have done a 12 volt battery load test in their process. Maybe they did and it was ok?

    (I wouldn't put it past them to not do it, but customer comes in with starting issues...?)
     
  9. bisco

    bisco cookie crumbler

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    the smart key computer would certainly be unusual. how many miles on her? are you the original owner?
     
  10. Prius0722

    Prius0722 New Member

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    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.
     
  11. Raytheeagle

    Raytheeagle Senior Member

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    You can get a cheap multimeter from Harbor Freight for under $10 (or free with a coupon and buy some other tool;)).

    Testing the battery voltage is easy at the under hood point. Open the fuse box and lift the red cover which is the positive terminal. Then find any metal in the engine bay for the ground and you have the connections needed for the multimeter to test the voltage;).

    The dealer you are using is not helpful or does not understand the difference in batteries:(. Mind sharing the dealer as others may benefit from your experience?

    If the voltage is higher than 12.5 v after sitting overnight, battery should be in good shape. Otherwise, it is past its prime. I bought our 2010 Prius II in August 2009 and still have the original 12v battery. I check it periodically and last weekend got 12.81v after sitting overnight. So still running strong:).

    Hope this helps and keep us posted(y).
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    That sounds like a good place to avoid. Any competent retailer of batteries should be capable of checking the health of the 12 volt battery. They have the "big brothers" of something like this (Solar BA5, by Clore Automotive), which I use:

    upload_2016-11-17_8-2-10.png

    It checks voltage, but more importantly, does a digital load test, reports the actual Cold Cranking Amps, and gives a rudimentary diagnosis.

    Maybe with the AutoZone idiots, remove and bring in just the battery, and then they'll test it? Or find some place more competent, if that's still possible. Maybe resign yourself to paying someone, then your options improve.