RTOD – how bad can it be?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jim x 3, Jul 12, 2025 at 8:35 PM.

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  1. Jim x 3

    Jim x 3 New Member

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    My first chat post. Please be nice.

    2007 Prius.

    3/24/2024 96,385 miles: HV battery was replaced with a new Toyota battery
    4/22/2025 125,840 miles: the RTOD with P3000, P3020, B1421
    Battery Block 10 weak
    7/7/2025 133,352 miles: the RTOD with P3000, P3020, B1421
    7/10/2025 600 miles later: same DTCs again
    7/10/2025 40 miles later: same DTCs again

    OK, so I’m starting to pay attention. Block 10 voltage is 15.80. Next (lowest) is block 4 15.99. Highest block voltage is 16.16.

    Is it the “red triangle of death”, or “doom”?

    What should my next steps be?

    Thanks and regards,

    Jim x 3
     
    #1 Jim x 3, Jul 12, 2025 at 8:35 PM
  2. dolj

    dolj Senior Member

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    You don't say who replaced it, but if it were an OEM new fitted by Toyota, it should still be under a 3-Year warranty.

    If it were an OEM new part fitted by a non-Toyota shop, it still should have had a 1-year warranty, which would have just run out by 29 days when the problem first occurred. I would have tried to have it replaced by Toyota at that point through the original shop. However, you are 3 months on from that now, so if it were not Toyota, it has become a whole lot harder to claim a warranty replacement.

    Having said all that, it is very unusual to have a new Toyota battery fail in such a short time.

    Maybe there is more to this story you are not telling us.
     
    #2 dolj, Jul 12, 2025 at 11:08 PM
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  3. Jim x 3

    Jim x 3 New Member

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    Thanks for your reply.

    I don't have any secrets here - what can I add?

    I purchased the replacement from a Toyota dealership parts department. The part cost about $1950 with a $1300 core charge. I did the work myself. I'm not an auto mechanic but I had the requisite tools. I am a professional electrician - the system design was well understood and the swap was straightforward with no surprises. I picked up the new battery in its sarcophagus on a Friday and did the swap over a weekend. The sarcophagus on the pallet does fit in the hatchback with the rear seats down.

    The car previously belonged to my parents and it did not do well since they were old and did not exercise it regularly. My impression is that a 2 or 3 months interval between uses is death for this car. They are now gone. Conversely, my daily commute is about 75 miles 1-way. Almost all of that is freeway miles at high speed, 55-85 mph with frequent accelerations and decelerations for traffic. Cruise control is never possible. My mileage has been consistent and good - about 43 mpg.

    Since there was a simple 1 year warranty, I didn't think it fair to ask Toyota for any consideration.

    What else do you need to know?

    regards,
    Jim x 3
     
    #3 Jim x 3, Jul 13, 2025 at 12:30 AM
  4. Tombukt2

    Tombukt2 Senior Member

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    Master warning light hath nothing to do with any deaths . Master warning is oil. water temp or look at these other orange lites puhleez.
     
    #4 Tombukt2, Jul 13, 2025 at 12:56 AM
  5. dolj

    dolj Senior Member

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    The Master Warning Light comes on when there is a hybrid system problem.

    Oil, water temp, etc, will be signalled by the MIL (message information light), AKA check engine light (CEL) or on the MFD by way of an icon on the top status bar.

    He's right, though; there are no deaths.
     
    #5 dolj, Jul 13, 2025 at 3:07 AM
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  6. ChapmanF

    ChapmanF Senior Member

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    And to the OP's question, there are a couple hundred different choices for "hybrid system problem" that can make the Master Warning Light come on. They can range all the way from "you need a new transmission" or "you need a new battery" down to simple issues you fix in 5 minutes and you're on your way.

    So it's almost perfectly useless trying to guess. Read the trouble codes that say why the light has come on, and then there's more to talk about.
     
    #6 ChapmanF, Jul 13, 2025 at 10:15 AM
  7. dolj

    dolj Senior Member

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    I wasn't meaning to imply you were hiding anything, but it did feel like there was more to know. You provided more details in your next post. So, unless you inadvertently did something (or failed to do something) during the install, then it is unusual that you should be getting the bad block DTC.
    Even so, there is a reasonable expectation that the battery should last 8 to 10 years. Given that, I would expect Toyota to be receptive to warranty support, given that it failed in 12 months, 29 days. I guess they would need to be assured that the installation was done correctly and did not contribute to the failure.

    I don't know that there is much more to add.
     
    #7 dolj, Jul 13, 2025 at 11:10 AM
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