RTOD (Red Triangle of Death) after hard braking - running on engine only

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LKasdorf, Jun 5, 2021.

  1. LKasdorf

    LKasdorf Junior Member

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    2005 prius 150k.
    I was driving today and had occasion to brake hard, going abut 40, and the tires screeched briefly. It was not a real emergency stop, but I had to slow faster than I intended. Stuff in the car all came forward, but then all was ok. Except...
    The red triangle came on, along with the VCS, the circle in parentheses, and the pink car with exclamation on the center console. Also, cruise control no longer works.
    The car still runs, but looking at the info screen, it was seemingly only running on the engine- not on the battery at all. I have not yet done a scan for codes- will do tomorrow. I did disconnect the battery and try again- the RTOD was off at first after starting, then came on. I also did the computer reset- ODO & brake while shutting down and back on. No change.
    I don't understand how hard braking could trigger this. It seems like some fuse related to the inverter must have blown.
    This car did have the inverter coolant pump failure and was replaced at the dealer under recall.
    Any guesses?
     
  2. SFO

    SFO Senior Member

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    Disconnecting the 12v battery will erase the store codes (DTCs), always best to first read and record them before disconnecting.
     
  3. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Oh heck, after fruitless googling, I finally twigged:

    RTOD = Red Triangle Of Death

    Give everyone a break; don’t make up acronyms, using popular but very unofficial terms??
     
  4. ChapmanF

    ChapmanF Senior Member

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    Even better, think about it by its official name, the Master Warning Light (MWL). There are a lot of reasons that light can come on, some of them more bureaucratic than catastrophic. Calling it the Red Triangle of Deeeeaaaaaaaaathhhh tends to put people in the wrong frame of mind for just finding out why it lit up, and moving along.

    I'll be curious to see what trouble codes you have, once you can post those.
     
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  5. LKasdorf

    LKasdorf Junior Member

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    After struggling to get my phone to connect to a bluetooth odb adaptor (why is is this always so hard?), Dr Prius shows P3000 and P084 battery codes, and no ECU codes. It also shows the battery voltages looking pretty OK. We have 3 gen 2 priuses and I installed a grid charger on all. So, I have been in there messing with the connections to the HV battery and the cooling fan.
    Since a mechanical action (slamming the brakes) triggered this, I have to think that something shifted and opened a connection.

    Sorry about the acronym- I thought RTOD was common parlance. It is used a lot on this site.
     
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  6. ChapmanF

    ChapmanF Senior Member

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    Every code comes from some ECU. The P3000 comes from the HV ECU (and all it means is "have you checked the battery ECU yet? it has codes for you."). For the battery ECU code, did you leave out an A ?

    P0A84 refers to a problem controlling the battery cooling blower. It's possible that your hard braking produced a heavy charging current that resulted in a call for a higher blower speed and led to a detection threshold being crossed. It seems plausible that the system might limit use of the battery when it knows of a cooling impairment.

    If those are really the only codes you've got, the P0A84 is the one I would look into.
     
  7. LKasdorf

    LKasdorf Junior Member

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    I meant to say no ENGINE ECU codes- which is the wording that Dr Prius provides. And yes, P0A84.

    I uncovered the battery and connections just now, as well as the patch into the cooling fan that the grid charger uses. I plugged in the grid charger and the cooling fan came on, and it appears to be charging normally.

    I've not yet checked all the fuses, but that is my next step.

    And here is a dumb question- is there a big fuse somewhere for the HV battery? I've not found any reference to it.\

    Also, I think I'll put a 12v charger on, in case its voltage is minimal.

    I do have techstream running on an old laptop. I will hook that up shortly.
     
  8. ChapmanF

    ChapmanF Senior Member

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    There is, and it's right in the service plug that you pull out before poking at the battery. But you don't have any codes indicating any problem there.

    In general, allowing your troubleshooting efforts to be informed by the codes you have will save you time.
     
  9. Tideland Prius

    Tideland Prius Moderator of the North
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    Could've just looked here :D <ducks>

    PriusChat Glossary | PriusChat

    RToD was a Gen 2 term.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    Still officially the Master Warning Light even then.

    mwl.png

    Less dramatic, sure, but more likely to put people in the right frame of mind for finding out why it turned on.
     
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  11. LKasdorf

    LKasdorf Junior Member

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    I found that the connector for the cooling fan has 2 corroded connections. Apparently this is a common issue? I'm going to bypass these connectors and install spade lugs.

    After I fix this, can somebody tell me the best way to tell the cooling fan to stay on high all the time? And is this a bad idea?
     
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  12. SFO

    SFO Senior Member

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    I've used the App called Torque to do this (see sig below), but there are other Apps that may do the same thing.
    May depend on the outside temps and the internal temps of the HV battery, high speed in the summer and default settings in the winter.

    Generally speaking most will find the HV battery fan is less expensive, and easier to replace than the HV battery itself.
     
  13. LKasdorf

    LKasdorf Junior Member

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    Ok-
    I bypassed those corroded pins, and I bench checked the relay. It was good and still same problem.
    I run techstream and it still reports P0A84 (battery pack cooling control circuit low).
    I tried the active test which is supposed to let you try the different fan speeds. It first says "error code 0xA1050301". I try again and it says "ECU cannot perform the requested active test".
    I wonder if techstream can be a little more specific?

    I have verified that the fan itself is fine, because my grid charger powers it full blast when it is charging.

    I tried Torque (pay version) and it gives a code P3190. If I ask it to clear codes, it does turn off the triangle and error lights for a few seconds, then they come back, then vanish again, then come back.

    I've been looking carefully at the wires around the HV battery ECU and reseating connectors. What is the next step? What would cause the err reported in techstream?

    Also, I don't see anywhere in Torque where I can force the fan speed settings. I've look for special prius plugins and not found.
     
  14. ChapmanF

    ChapmanF Senior Member

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    I have had Techstream active tests fail when using one dongle that would work when using a different dongle. What dongle are you using?

    The newly-appeared P3190 is kind of a curve ball. That's an unexpectedly-low-engine-power code. Unless it keeps coming back, I'd kind of table it for now, and keep working on the P0A84.

    P0A84 is reported when the voltage coming to the battery ECU on terminal VM is lower than it should be for the selected blower speed. VM is tapped from the low-side connection between the blower and the blower controller, so it would normally be highest at the lowest blower speed, and vice versa. There are about a dozen pages in the Repair Manual (more info) in the P0A84 section on how to approach troubleshooting; they also refer to a section later in the manual, "battery blower - on-vehicle inspection".
     
  15. LKasdorf

    LKasdorf Junior Member

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    I am using a mini-VCI cable.

    When you say "repair manual", do you mean the official Toyota manual? It appears that I need to pay $65 for a 2 day subscription to the professional diagnostic. Is there a cheaper way?
     
  16. SFO

    SFO Senior Member

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  17. LKasdorf

    LKasdorf Junior Member

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    Wow- EXACTLY what I needed! Thanks so much! I was getting really depressed about fixing this, but I have new hope!
    I have uploaded those files- where should I post a link (in this thread??)
     
  18. LKasdorf

    LKasdorf Junior Member

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    This is resolved now, mostly. I'm embarrassed to say that the problem was a blown fuse. I thought I had checked the battery fan fuse but apparently not. Replacing this cleared the CEL and other lights but not the red triangle. I had to connect to techstream and clear it there. If I had been able to connect to Dr Prius, I could have cleared it there as well.

    Sorry for all the brain power expended on a simple blown fuse.

    I still do not know how slamming on the brakes could cause that battery fan fuse to blow. All the wires are battened down and look fine.

    Usually when I try to connect to a bluetooth ODB device in DrPrius, I get a cryptic socket error. Sometimes forgetting the ODB and re-pairing does it- sometimes not. Sometimes I cannot get my phone to detect the ODB. I bought a fairly pricey Foseal wifi ODB device and I've never- not once- gotten it to work. Why is this so hard?
     
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  19. SFO

    SFO Senior Member

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    This thread is fine, always nice to have a backup available if another repository goes down.
    Sounds just like my newly acquired OBDLink MX adapter (BT version, discontinued), can't seem to pair it and will need to try following the instructions (hit the pair button, then pair within 2 mins). Don't have any issues pairing my old $1usd cheapo and using it with Torque.
     
  20. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Fuses often blow for a reason. Maybe fan is running overtime, on its last legs? This could be due to ailing battery, or lint clogging?
     
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