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  1. Bob likes hybrids

    Bob likes hybrids New Member

    Joined:
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    Location:
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    Vehicle:
    2005 Prius
    Model:
    One
    New to Prius chat. Been reading for a while, but my Prius has been so reliable, that I have not stopped by that often.

    I have a 2005 Prius. It has 120K miles on it. It has been the picture of reliability until 5 days ago. We went on a trip and left the Prius in the garage for 5 days. It was hot while we were away, but nothing Phoenix-like – just 100 degrees each day – here in Oregon.

    I came back and was ready to do some errands and started the Prius. Triangle of death, plus a few other lights came on. Did the check the 12 v check and it was low – 11.6-11.9 volts. Turn the car on and it popped right up to 14.2 volts. Ok – I thought I had been on borrowed time on the 12V (it drained a couple of times and I needed to charge it with my Jackery) – so I replaced it. I also purchased OBD plugin monitor and downloaded Mr Prius and paid the $13.99.

    Mr Prius came back with just one error code P03000 or something similar, which I think is just that the triangle and check engine light are on.

    I was able to clear the codes and start the car, but the symptoms started to change and things were spiraling downhill a bit.

    Mr Prius showed pack voltage of 230.28 volts, #1 was highest at 16.71, #2 was lowest at 15.19. All others were 16.49 to 16.65 volts. All the internal resistances were 19 m-ohms. 12 volt battery showed at 14.2 with the car running. (With the car off the new battery went from 12.1 when installed to 12.4 after driving around the block.)

    Here are the symptoms that concern me.

    1. I have never heard the battery fan running before, but now it is constantly on – presumably on high. Regarding that, Mr Prius showed 131-142 Deg F on the 3 areas in the monitor. Earlier, this had been 85, which was close to ambient temp. (The jump in temp has me worried, along the fan running, when I have never heard it before.) I just checked it again and they were higher 140-160F.

    2. There seems to be more clicking at the start than I remember – like connections closing or trying to close. I might be overthinking this.

    3. When looking at the hybrid level in the car display, the battery level would jump around, going down as low as 1 bar and then slowly work its way back to all bars except one. I never noticed it jump down, just that it was down. This is new.


    I can run whatever tests folks think of value and take screen shots.

    The car seems to run ok, but I did not like it that more things seem to be going off.

    I don't want to lose faith in the car.

    Ok - last - completely different item. Every time I get the car checked, the mechanic comes back with that the brakes are at 45-55%. I have never had them worked on. Same with my old Highlander Hybrid. If I brake slowly, do the brakes shoes last forever?
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
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    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    99% chance that you have a weak/failed module in the HV battery. Your HV battery is assembled using 28 individual modules, wired in series. Each module is nominally 7.2 volts (but typically around 7.8-8.0) The ecu measures voltage every two modules, thats why you see those values. Two modules together is called a block. That's why there are 14. Each individual module is a plastic case with 6 individual cells, each 1.2v nominal. When you see one block voltage ~1.2 v lower than the others, it usually means one cell inside on module has failed. Individual modules can be replaced relatively inexpensively if you're a decent DIYer. A well repaired (or better yet, a new Toyota battery) will return your car to it's previous glory.

    This post I made in this thread may help explain it better:

    Inconsistent Hybrid battery readings | PriusChat
     
    Brian1954 likes this.
  3. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
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    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Your battery is over 10 years old That's one box ticked The car is the same age as the battery I would imagine Just getting that time or you'll be changing out modules and parts under that battery hood until you finally decide maybe really should get a battery Don't waste a lot of time playing whack-a-mole and all that Just get a battery and you should be back where you are It's just that time the mileage comes slow for this car usually this vehicle will have 300,000 on it by now and be time for the battery.
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    get a free load test on the new 12 volt at many auto parts stores. if nothing else, it needs a charge