HV Battery wrong voltages on Torque

Discussion in 'Gen 2 Prius Technical Discussion' started by Jorge P, Nov 15, 2019.

  1. George W

    George W Active Member

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    Holy Smokes Batman! 'clean thoroughly..sockets on the ecu' and 'contacts wet' and 'battery contact cream' sound alot like you enabled a short
     
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  2. Jorge P

    Jorge P New Member

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    But it didn't explode... It is electrical mcicro switch cleaning. And tye cream is battery contacts. I will clean it all anyway
     
  3. dolj

    dolj Senior Member

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    I don't think anyone in this thread is suggesting that the ECU is the problem at this point. You have some investigation and testing to do before you can arrive there.

    See my post #13 for info that describes what is going on with the P0AC0 or SFO's post #20 which is the full workup for P0AFA.
     
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  4. Jorge P

    Jorge P New Member

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    Thanks! I don't have the testing equipment to do exactly the workup of post #20. The current sensor doesn't have too much to test. Just the ground wire, the sensor itself, and its connection to the ECU... Or the ECU itself.... my troubleshooting is mostly trial and error. My next two steps are to try a new ECU and swap some battery modules. I am starting with the ECU anyways and see what happens. I should get it by the 21st. Hope is a good one.
     
  5. dolj

    dolj Senior Member

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    Hoping and assuming can tend to lead to wasting time and money. Get the test equipment you need, or at the very least a middle of the line (as in, not the cheapest you can find) or better digital multimeter (DMM).

    But it is up to you how you go about it.
     
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  6. Jorge P

    Jorge P New Member

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    I have a digital multimeter and it helped me verify the modules and blocks. The techstream sounds like a fancy tool for Toyota techs. About how much is it?
     
  7. dolj

    dolj Senior Member

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    You need a windows laptop, preferably an old spare one so you can dedicate it to Techstream, plus an OBD-II to USB cable to connect it. A lot of people who don't need super reliable use Mini VCI cable, which is the cheapest $20-$40; then there is VxDiag which is a better cable ~$80; then Tactrix Openport 2.0 for around $169 (there are cheap knock-off of these, don't buy them) and then there is the Toyota tested Mongoose for around $495. Don't buy the knock-off Mangoose cables. The Mini VCI and VxDiag cables come with Techstream. I'm not sure if the Tactrix Openport 2.0 one does.
     
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  8. Jorge P

    Jorge P New Member

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    Thanks for all of that info, this is probably going to be a one time experience for me doing this type of repair. I have a few old laptops, the OBD-II I got is a wifi one. It is working fine with my Android S10.. I will get back to the Prius project late this week. Will post updates.
     
  9. Jorge P

    Jorge P New Member

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    Update: I bought an ECU on ebay and installed it today. Now the Torque scan shows zero errors!!! and the voltages for each block are 15.4V or 15.5V I guess this is good - but the car still doesn't start... I also replaced the aux. battery which Advance Autoparts tested and said it was bad. I bought what Discount Autoparts offers, not the original Toyota... pictures attached. Thanks all for the help. Screenshot_20191121-162637_Torque.jpg
     
  10. Prodigyplace

    Prodigyplace Senior Member

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    Aux Battery 11.4 volts is too low!
     
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  11. Jorge P

    Jorge P New Member

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    Yes, I brought it back to Advance Autoparts and it tested OK there.... 12.2 Volts and good CCA... But for some reason Torque shows only 11.4V. or so. I also tried one time jump starting without success - And I think jump starting is what killed the first ECU....
     
  12. dolj

    dolj Senior Member

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    It may have tested good, but it is essentially flat at 12.2 V. You need to put that puppy on a charger and get the voltage up to 13.2 V (or at least 12.9 V). Then it is fully charged.

    Having said that, the state of the 12 V is not your problem.

    You cleared the codes after installing the new ECU, didn't you? You also installed the HV safety interlock correctly, yeah? Seems it is easy to miss step 3.

    Prius safety Interlock.jpg
     
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  13. TMR-JWAP

    TMR-JWAP Senior Member

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    Jorge,

    Glad to hear you're making progress. Any time you disconnect the 12v battery, the power button must be pressed 2 times. Put your foot on the brake and press the power button once.(Your dash will now look similar to your photo with all the alarms). Maintain your foot on the brake and press the power button again. If everything is "normal", all the alarms will clear and the car will go ready.

    If this is not happening, can you describe step by step what you are doing and the condition of the dash lights?
    Do your brake lights come on when you press the brake pedal?
     
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  14. Jorge P

    Jorge P New Member

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    Thx. Yes, I will bring it to Autoparts again and ask them to charge it for a couple of hours. I didn't miss step 3. I will also make sure no wire was left disconnected near the ECU I know the ones that go to the ECU directly are all connected.

    I didn't clear the codes. They cleared themselves. I mean no codes show up when I click on "fault codes" in the Torque app. It goes to 100% and comes back with 0 errors...
     
  15. dolj

    dolj Senior Member

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    It will need to charge for much longer than a couple of hours.

    Also, if it were me and they tried to sell me a new battery that was only 11,8 V, I would reject it and ask for another that is at least 12.9 V and if AGM, it should be at least 13.2 V. Who knows how long that battery has sat nearly fully discharged and all the while it is sitting in that state it is irreversibly being damaged. If you accept that battery, don't expect it to last for very long – a year or two at the most.
    Check particularly the one below the safety interlock. It is a single black wire, I believe.
     
    #35 dolj, Nov 21, 2019
    Last edited: Nov 21, 2019
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  16. Jorge P

    Jorge P New Member

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    Thanks Jim,

    I will try all of that after I get the new aux. battery fully charged.

    * One thing that I have noticed is that the ready sign or light that used to flash during starting up, is not flashig at all...

    * Also, Do you guys think the torque on the contacts of the HV battery modules could be causing this?
    I dont have a professional wrench.

    * What do you think of jumpstarting this Prius.

    I think it all started because I didn't notice an interior reading light in the back of the car was left ON for days... Sometimes I leave this car parked for a couple of weeks...

    I had to jumpstart it. and I did it by connecting the cables directly to the 12V battery...
     
  17. dolj

    dolj Senior Member

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    You didn't think to mention that at the start?

    Are you 100% sure you connected the jump cable correctly, red to +ve and black to -ve at both ends?

    Running the 12 V battery flat, as you did and then it sat like that for who knows how long was probably the death knell of your original battery.
     
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  18. Jorge P

    Jorge P New Member

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    OK Definitely, I will ask for another one. I think they have two that fit the Prius at Autoparts. Not sure if they have AGM. Is that better? This one I just got was $220
     
  19. Jorge P

    Jorge P New Member

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    Sorry, the main issue for this thread was the hv battery assembly with ECU Yes, 100% sure +ve and -ve connected right. The 12V battery was about 8 years old. But could the jumpstart be what killed the ECU too? I connected directly to the battery not to the possitive port by the engine in the front. The 12V battery was weak I did have to jumpstart a few times after that light was left ON...
     
  20. dolj

    dolj Senior Member

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    Hmm, Interesting.

    Your description sounds a lot like a jump gone bad. Check the 100 A fuse in the +ve terminal block at the battery, and also the big fusible link in the main fuse box at the left (as you sit in the driver's seat) of the engine bay.
     
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