1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Unable to determine the cause of the triangle warning

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by veggiecar, Feb 18, 2015.

  1. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    I have a 2005 Prius with 240,000 miles. About 4 months ago the triangle warning symbol appeared. A friend and I decided to pull the big battery out of the car and find the bad cells. We did that, replace two and the car worked fine for 4 months. The triangle warning has returned. We have done several things but the triangle remains. We pulled the big battery out and checked all of the cells. We replaced one that was probably OK. The latest reading was 8 volts on cells all but one at 7.9. We cleaned all of the bus contacts. We went into the maintenance mode on the MFD and found the aux battery to be 12.6 volts and under load it dropped to 11.8 with the lights on. The aux battery went up to 14.1 volts with the car on. The inverter cooling fluid has movement and there is a slight humming which I believe to be the inverter pump running. The inverter fluid was topped off. The MFD showed the battery bars start at about three fourths full, drop down to one bar. With the engine running the battery bars climbed to the top purple. The engine turned off and the bars continued to climb to all green. All of this occurred in about 3 minutes while the car was parked. There were codes on the MFD while in maintenance mode. I understand that these codes are for the navigation system and the audio system. Any suggestions on the next step in solving this problem... Thanks for the help.
     
  2. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,831
    1,824
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    Did you:
    1. Load test the modules - A good cell can deliver a high current for a short time and recover to nearly the same voltage when the load (use both filaments of a halogen headlight).
    2. Did you measure the series resistance of the modules - A capable, Prius aware OBD2 can read these values out from the Battery ECU.
    Any module that behaves differently from the others in these tests is bad and will cause error flags to be set.

    JeffD
     
    #2 jdenenberg, Feb 18, 2015
    Last edited: Feb 18, 2015
  3. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    Thanks Jeff ... I will work on your suggestions. I have an additional piece of information. We reset the fault (got rid of the red triangle) by disconnecting the aux battery. Drove the car. After about a mile the cooling fan in the back of the car (attached in the black ducting that goes under the big battery) came on and when it came on the red triangle reappeared.
     
  4. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,831
    1,824
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    This means your battery is overheating which can weaken additional modules.

    JeffD
     
  5. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    Jeff ... Do you have any suggestions on what might be causing the problem? How I might isolate the problem? How I might fix the problem? Is the fan in the back attached to the black ducting supposed to run before the battery gets hot? The fan came on when the battery was considered hot. Thanks again
     
  6. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,831
    1,824
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    You probably have one or more modules with a high series resistance. They get hot when the battery sources or sinks current and their voltage fluctuates widely setting the flags.

    JeffD
     
  7. strawbrad

    strawbrad http://minnesotahybridbatteries.com

    Joined:
    Aug 9, 2011
    953
    993
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    II

    Get a Mini VCI cable and Toyota Techstream software. The cables are available on ebay or Amazon for $25. Without Techstream you are trying to fix your car in the dark. With Techstream you can look at live battery data while under charge and discharge. Weak module pairs will stand out with larger voltages swings.
    Static module voltage does not give a complete a picture of module health.

    Charge test : Engine on, set parking brake, car in drive, step on gas and brake fully. Your car will just sit still and charge. Give it about thirty seconds to a minute. The weak module pair voltages will rise faster and higher than the rest.

    Discharge test: Car on and warmed up, engine off, set parking brake, car in reverse, step on the brake, give it a little gas but not so much that the gas engine turns on. The car will sit still and discharge the battery. Give it about a minute. The weak module pairs will drop in voltage faster and farther.

    Brad
     
  8. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    Thanks Brad ... I actually have ordered the Mini VCI. I thought it would arrive today, but it did not. I will post how things worked out once I get the cable and run the tests.
     
  9. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    I got the Mini VCI and loaded it on a 32bit XP Pro laptop. I plugged it into the car. The software recognized the car and asked if I wanted to check the battery. It gave two codes 1) P0A80 which it said was: Replace Hybrid Battery Pack 2) P3020 which it said was: Battery Block 10 becomes weak. I am assuming that means to replace the 10th modules. My question is which side do I count from. Is it the end that comes apart or the end with all of the electronics? Thanks so much ...
     
  10. strawbrad

    strawbrad http://minnesotahybridbatteries.com

    Joined:
    Aug 9, 2011
    953
    993
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    II
    After you run the "Health Check" there are a couple of other things to look at. Some of the codes will have little snowflake Icons. Clicking the icon will get you into the freeze frame data. This is where you will find the sub codes. Another check is to click on the battery category on the left side of the screen. This will lead to the live battery data. Run the discharge and charge test!

    Battery Blocks are pairs of modules. So block 10 will be the 19th and 20th modules. The Toyota repair manual and most people on Prius Chat will tell you the count starts at the battery ECU.

    In my experience the count starts opposite the battery ECU. You will find a module 1.3 volts below the rest. Let us know what position you find it in.

    Let The flames begin.:eek:

    Brad
     
  11. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    I attached the Mini VCI to the car and it gave a huge amount of information. I ran the charge / discharge tests and as explained I could see the bad block voltage increase and decrease at a faster rate than the rest of the battery pack. Unfortunately I have not received my replacement modules as of yet so the car is still not operational.

    Two interesting points. When I originally started working on this problem the bad module was not apparent by testing the voltage. I think this might be the case because when you turn the car off, the battery charge is not always the same. If the battery pack was charged all of the modules would be high as occurs during the "charge test". My thoughts are that you must run the "discharge test" to find the bad module with or without the Mini VCI. Running the "discharge test" lowers all of the modules but it will lower the bad module to a much larger degree making the bad module very apparent.

    Another observation is that the module that I believed to be bad appears swollen. It has a noticeable bulge. This bulging of modules makes it very difficult to put the battery pack back together. Does a module that has a bulge indicate that it is bad or going bad?

    JeffD talked about measuring resistance. The Mini VCI reported all blocks at 0.019 OHMs. Is this the measurement of resistance of which I should be aware?
     
    #11 veggiecar, Feb 25, 2015
    Last edited: Feb 25, 2015
  12. jdenenberg

    jdenenberg EE Professor

    Joined:
    Nov 21, 2005
    3,831
    1,824
    1
    Location:
    Trumbull, CT
    Vehicle:
    2020 Prius
    Model:
    LE AWD-e
    Doing a load test on a module using both filaments of a halogen headlight would detect this as well.
    That indicates that the module has been overheated and should be discarded. The adjacent modules may have been aged by the added heat as well
    Yes, that is the easy way to get a resistance measurement, but it is for two modules in series. I am surprised that the bad module didn't show a higher resistance.

    JeffD
     
  13. strawbrad

    strawbrad http://minnesotahybridbatteries.com

    Joined:
    Aug 9, 2011
    953
    993
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    II

    In what position did you find the bad the bad module? To match Techstream what side of the pack did the count start on?

    I agree get rid of the bulged module. When I reassemble a Gen II pack I remove the compression tubes and plastic end plates from the metal case bottom. Fill the compression fixture with the modules and tighten the end plates. Flip the modules upside down. Set the case bottom on the modules and install the million mounting bolts.

    I have seen Techstream report a range of 19 to 23 milliohms for internal resistance. With such a small range I have not found it of much use.

    Brad
     
  14. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    Brad

    The count appears to start from the end opposite the ECU. Facing the battery from the back of the car the count is from right to left.
     
    strawbrad likes this.
  15. veggiecar

    veggiecar Junior Member

    Joined:
    Feb 17, 2015
    51
    5
    0
    Vehicle:
    2012 Prius
    Model:
    N/A
    The replacement modules arrived today. I tried to discharge the battery but the engine kept coming on. I presume that was because I did not let the car warm up as Brad told me. We took the hybrid battery out of the car and tried to confirm the bad module by measuring the voltage but all of the modules measured a little above 8 volts. We decided to replace both modules in what we thought was block 10. Block 10 is made up of the two modules that the heavy orange cables are hooked to. After replacing those modules the triangle disappeared. We have driven the car some and the triangle has not returned as of yet. I'll post again if the triangle returns. Looking at the screen from the Mini VCI and software after replacing the modules it still shows "P0A80 which it said was: Replace Hybrid Battery Pack". There is a magnifying glass icon on the line with the code. When I clicked on it a box pops up that says: Non Continuous - Failed last trip - Run monitor again to confirm.

    I now have 5 modules that I have replaced. What I would like to do is test them to see if any are good. Is there a procedure for doing this? Brad and JeffD ... Thank you very much for the help
     
  16. stonerider

    stonerider Member

    Joined:
    Aug 21, 2014
    107
    19
    0
    Location:
    Lompoc, CA
    Vehicle:
    2007 Prius
    Model:
    N/A
    Sorry to chime in, since I don't have answers, however this is one of the most instructive posts I have seen. I picked up a thing or two about techstream and HV batt.
     
  17. strawbrad

    strawbrad http://minnesotahybridbatteries.com

    Joined:
    Aug 9, 2011
    953
    993
    0
    Location:
    Minnesota
    Vehicle:
    2005 Prius
    Model:
    II
    You need a way to charge and discharge the modules. As Jeff said a Halogen headlight can be used as a load. Most use a RC model charger to charge the modules. I have used a 12 volt lead acid car charger on the lowest 2 amp setting. Since its voltage is much higher than the module it will put out 30 amps. I limit the charging to ten second bursts. Modules should be clamped while charging to prevent swelling. Get the modules charged to 7.5 to 8 volts. For a good comparative test you want the modules to be at the same SOC (voltage) at the start of the load test. This is done by connecting the modules in parallel. I use a really fine 30 ga wire wrapped around the terminal studs. I get the fine wire my stripping the insulation off an old extension cord and using just one strand. The fine wire will act as a fuse in case things go bad. Let the modules sit overnight while connected in parallel. You will also need a volt meter to run the load test. Alligator clips on the voltmeter lead would help. Hook up the voltmeter and the the headlight to a module. Time how long it takes to drop to any given voltage. I would use 6 volts. Another option is to run the load for a set amount of time ( a minute) and record the ending voltage. All of this is just comparing the group of modules that you start with. The clunkers will stand out.

    The codes in your car should clear on their own after a few driving cycles. Techstream has an eraser icon at the bottom of the screen also. It would be informative to run another charge and discharge test on your repaired pack. The results could show how long you have until the next module replacement.

    Brad
     
  18. Lesk_The_Glut

    Lesk_The_Glut Junior Member

    Joined:
    Apr 24, 2015
    52
    22
    0
    Location:
    Bakersfield, CA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Man, I wish I'd seen this before I rebuilt my pack! It was quite a feat to get those modules and end cap back on the pack! Now that I see your method, it seems so obvious, LOL!