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Newbie to Prius Troubleshooting

Discussion in 'Gen 2 Prius Main Forum' started by Popcornfamily, Jun 12, 2018.

  1. Popcornfamily

    Popcornfamily New Member

    Jun 12, 2018
    2006 Prius
    I had to "opportunity" to travel over 300 miles last Friday night to retrieve my son and his car, a 2006 Gen II Prius. He was traveling home from a wedding and saw his bars stating his charge move lower and lower without the ICE starting in order to recharge the battery. Fortunately he was able to get off the freeway to a gas station. I took a car trailer up there to tow him home. My day job is head of maintenance at a wholesale nursery. I'm not afraid to jump in to things to try to get them back up and going. I must admit, this one may be over my head. His car has 137377 miles on it. He's driven it to and from Texas for school with no issues. I'm thankful he wasn't in Texas at this time. He has owned this a little over 6 months and it has been a great car to date. We replaced the 12 volt battery about 6 months ago but other than that, basic maintenance.

    I thought that the hybrid battery must be failing and after a crash course and a number of Youtube videos, I opened up the access to the hybrid battery. The individual cells were all within .15 volts of each other. They ranged from 7.35 volts dc to 7.49 volts dc. I noticed some green corrosion on the copper bus bars connecting each cell so I removed all of them and cleaned and polished them and reconnected the batteries. I checked the voltage total and had 209 volts dc coming out of the battery. Is it possible that in spite of what appears to be appropriate voltage readings that the current supply within the cell is depleted?

    Aside from this, where do I go next to attempt to troubleshoot this vehicle? Can I take some simple steps before loading it up and taking it to a dealer. I must confess, some of the computer controlled mechanical equipment is a little intimidating.

    Here is my son's account of what took place: I was driving home for close to an hour and going around 65mph when suddenly the triangle came on and so did a warning on the screen. It just said problem and take to a Toyota dealer. When the warnings came on I felt the power to the accelerator give out and I slowly was losing speed. I got to an exit and had to stop at a signal. When I started to go I was flooring the pedal and barely able to go 10 mph and then I stopped at the gas station.

    Well, there it is. Welcome to the Prius world.
  2. bisco

    bisco cookie crumbler

    May 11, 2005
    2012 Prius Plug-in
    Plug-in Base

    the battery has to be tested under load. you can either purchase tech stream software on line, and an old compatible laptop, or you can remove each module and load test with a light bulb.

    there are many threads here describing both procedures. diagnosing and rebuilding a battery is painstaking, but cheap if you have the time. reliability is sketchy though.

    try calling toyota and asking for goodwill warranty help on a new battery, you never know.

    all the best!(y)
  3. Wayne

    Wayne Active Member

    Aug 11, 2005
    Fort Wayne, IN
    You might want to take it for a quick test drive around the block to see if most of the power is back. What you describe happened to me when my hybrid system failed and the gas engine had to do all the work. The result was a gas engine that got too warm. This could be because of any number of high-voltage reasons. For me, my hybrid battery got too weak.

    When the gas engine carries too much of the load, it stops charging the hybrid battery. If you have something like an air conditioner on, the high voltage battery will quickly deplete. When things get bad enough, the car will stop using the hybrid battery altogether, and all symbology to it on the display will stop. Your car will lose acceleration, and not have a very high top end speed. It may idle at 40 or 45 MPH, but you may not be able to go much faster. Flooring it will not do anything for you when you are in that state.

    In my case if I cycled power most symptoms were gone until the engine was sensed as being too hot again.

    If it is a problem with your high-voltage system, then the best thing you can do is limit your miles, start out and drive slow, stay off highways, and don't jump out into traffic. And don't use the air conditioner, because you want the high-voltage battery to retain some level of charge (if the system is still capable of recharging it).

    Hopefully a test drive around the block will go well, as the gas engine should be cool now. If so, you should be able to get it somewhere where you can have your codes read. Or you can use your trailer. For me, I was able to drive to & from short distances (up to about 5 miles) with only a hesitation when starting out. So no matter what, because of the hesitation (and possible overheat condition) always leave plenty of room when pulling out into traffic. And get those codes read.
    #3 Wayne, Jun 14, 2018
    Last edited: Jun 14, 2018
  4. Raytheeagle

    Raytheeagle Senior Member

    Jul 1, 2016
    Bay Area, California
    2019 Prius Prime
    Prime Plus
    Welcome to Prius Chat (y).

    Some questions:

    • Are there any dash lights displayed?
    • Do you have a way to read the codes?
    • When your son bought the Prius, did it come with maintenance records?
    • Had the inverter water pump ever been replaced?
    • Hybrid battery fan been cleaned?
    • Has your son ever heard the fan run?
    As @bisco mentions above, Techstream is the software to use for troubleshooting :).

    I’d look into getting that software for diagnostics to help before a shot gun parts replacement approach or jumping in head first;).

    Good luck and keep us posted (y).
    #4 Raytheeagle, Jun 14, 2018
    Last edited: Jun 14, 2018
    dolj and ITBland like this.