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Burning smell, followed by death. Inverter itself or pump?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ryguy, Apr 12, 2023.

  1. ryguy

    ryguy Junior Member

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    So the prius recently took a crap. When I was accelerating up a hill the red triangle of death came on. VSC and all other lights came on as well. Turned it off a bit later and turned it back on and VSC went away but other lights remained. Not sure if this is related but when it got cold this winter the dash would flash or pulsate extremely noticably until the car warmed up completely. I also noticed very rarely the dashboard would go out completely when driving up a hill. This happened ONLY when driving up a hill and this is also when the red triangle of death came on, so I thought that might be related somehow. Anyway, the car was ok on a long drive to work and got me back home and back to work again the next day. During that time, I got the codes from autozone and it indicated a problem with the inverter pump. From the video I watched, it said that if you saw movement in the reservoir, your pump was still good. Opened it up and sure enough there was movement in the reservoir. I thought ok, this seems like just a false alarm, since I had been driving forever with CELs on in my driving history and had fairly good luck in the past lol. But today, after inflating my tire with one of those 12v dewalt inflators, I noticed a burning smell in the car when I got in and noticed the plug was EXTREMELY hot on the dewalt. My first thought was "this is dumb as hell but I have to try to drive this thing to work so I don't get fired" since I was already running late from having to pump my tire up. So naturally, I got about a mile before the burning smell got worse, followed by the car completely shutting down and having to glide to the side of the road. I saw in a video where it was mentioning letting the car cool down and trying to start it up again and limp it home/to a shop, so I walked back to my car and tried this after a few hours. Nothing. Wouldn't even try to start up. But the weird thing is that my smartkey, beeping when the door is ajar, all that kinda stuff is still working.

    What's confusing to me is most of what I'm reading would indicate that it's the inverter pump, but then I saw it working, or at least partially working because of the movement in the reservoir. I also called Toyota and they told me this was replaced under recall in 2013 and it seems to be a pretty durable item since most manufacturers I've seen are offering lifetime warranties on them. One of the huge issues is that I'm absolutely awful with cars/tools. Like, legendary bad. To give you an idea, I felt very accomplished after replacing the license plate bulbs a couple days ago. Yeah... bad. Can anyone give me some insight into what I might be looking at or what my next steps might be? I don't really have the money to take it to toyota or a shop and I'm going to be absolutely screwed for work.
     
  2. ChapmanF

    ChapmanF Senior Member

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    It's not uncommon for the inverter pump to fail. And it's not uncommon for it to let out stinky smoke when it fails.

    But that doesn't mean all stinky smoke comes from the pump. The pump is out under the hood and that's where its stink should be strongest. If you smelled a stink inside the cabin, and your inflator's plug was extremely hot, maybe you don't need to look further than that for the stink.

    The combination meter getting flaky is another thing not uncommon in Gen 2. It seems to be a straightforward repair (if you can replace a capacitor on a circuit board) but it can cause all kinds of mischief including the car not turning on (or the car not turning off!) when it isn't fixed.

    It sounds like you've been driving that way for a while. I usually strongly recommend trying hard to stay on top of issues as they arise, just because it can get pretty complicated to diagnose what's going on in a car after there are two or more issues in play, and perhaps interacting.

    I'm a little worried this'll be like that. But there was definitely a stink, and then some stuff definitely stopped happening, so maybe it wouldn't hurt to go through and check all the fuses. Not necessarily to change any of them yet, but if you find any blown, let us know which ones.

    Also, see if you can describe for us as clearly as possible exactly what does and doesn't work. Can you go to ACC (one button push, no brake) and play the radio? Can you go to IG ON (next button push, no brakes) and get things lighting up on the dash? Which things? Will things like the turn signals or wipers then work? Then what happens if you try for READY (button push, foot on brake)?
     
  3. ryguy

    ryguy Junior Member

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    Button push without brake doesn't work. Button push with brake doesn't work. Car doesn't illuminate or do anything at all. The only time I heard it do anything was when I was trying to pry one of the fuses out by hand(unsuccessfully), then it finally made a noise, not too dissimilar to the noise it makes when you shut down the car, I believe it is the brake actuator?
     
  4. ryguy

    ryguy Junior Member

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    Something I just remembered that I didn't add was that, strangely, the red triangle of death wasn't on when this was burning up for some reason. I guess maybe because it lost connection with that part completely when it died out? But you'd think that the red triangle would remain??
     
  5. ChapmanF

    ChapmanF Senior Member

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    Taillights? Headlights? Hazards? Horn?
     
  6. TMR-JWAP

    TMR-JWAP Senior Member

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    Everything you mention points to the Inverter Cooling Water Pump frying and taking out the AM2 fuse in the underhood fuse box. Unplug the pump and replace the fuse. The fuse box has a spare 15A fuse stored inside it. Replace the pump the first chance you have. You'll probably find that the underside of the pump is slightly melted. Until you replace the pump, the car will typically allow you to drive at low speeds and low loads (ie not big uphills), but highway speeds will cause the inverter to overheat.

    You can unplug the pump at the pump or by using the single wire plug taped to the wire harness just above and to the left of the underhood fusebox.
     
  7. JoeVR

    JoeVR Junior Member

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    This same thing happened to me a few weeks ago -- I had no response whatsoever when I hit the start button, no lights, no nothing - and I smelled this terrible burning smell. Fortunately, it was in my driveway.

    It turns out it was the coolant pump for the inverter, and it blew a couple of fuses. Once the coolant pump was replaced and fuses were replaced (I can't remember which one, but it was a 15-amp, I believe), everything came back to life.

    Hope that helps
     
  8. edthefox5

    edthefox5 Senior Member

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    Pump death will always throw a Red Triangle of Death.

    Since you cooked the system it will require a flush and replace of Inverter coolant Toyota LLC. Then a bleed of the pump.

    Do not buy a pump at a parts store. Waste of time and money you will be right back in there soon after. Buy the Toyota Denso pump only.

    Best way to get to the pump is pull the front bumper off. Then your view of the pump looks like this:
     

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  9. ColoradoCrow

    ColoradoCrow Active Member

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    Definately sounds like the invertor pump. if you have 125K or more and it has never been changed DO IT! lots of videos on you tube. Reemove the drivers headlight first...much easier. have a friend watch the video and help you...or two friends....buy a GENUINE TOYOTA PUMP $180 at the dealership...less on AMAZON. Not the crappy $65 ones..
     
  10. edthefox5

    edthefox5 Senior Member

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    Why are you quoting me and repeating what I just said.?
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    Why are you quoting me and repeating what I just said.?

    Probably because he had some questions and just forgot to ask.

    Pump death will always throw a Red Triangle of Death.

    Not always. There are probably many dozens of lightly used Gen 2s running around right now that have failed inverter cooling water pumps and the owner will never know. There's probably a lot of them that are taking their cars to a shop and spending $$ having the AC system worked on because it's functioning intermittently, not realizing it's because the inverter is getting warm. The pump failure itself does not give the Master Warning unless the inverter actually overheats. If in complete electrical failure and it blows the AM2, the car just shuts off, dead as a brick.

    Buy the Toyota Denso pump only.

    Someone will have to show me those markings, because I've never seen them. Toyota and Lexus Genuine Parts, yup seen those markings every time. Anyone looking for a Toyota Gen 2 ICW pump with Denso markings or labelling is going to be looking for a long time. I've always thought they were manufactured by AISIN, their part number WQT800 and unmarked for Toyota, but I could be wrong. It happens. These are available (without Toyota packaging) from Rock Auto for less than a hundo.

    Best way to get to the pump is pull the front bumper off.

    Even easier if the driver headlight were removed so it's not in the way. Bumper doesn't need to be removed, just the driver side loosened a bit to access fasteners. Use some medium sized hose clamping pliers and it's a pretty quick job with little mess.

    And I'm very fortunate because my local dealer only charges about $125 for this pump.
    Toyota Prius Drive Motor Inverter Cooler Water Pump - G902047031 | Jim Hudson Toyota, Irmo SC
     
  12. ryguy

    ryguy Junior Member

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    Anyone else have opinions on whether a flush of the coolant is necessary? None of the videos I'm seeing online where they burnt their pump up are doing a flush on it? This is the first I'm hearing of that. Not saying this is wrong but I'd like to get a couple more opinions on that.
     
  13. TMR-JWAP

    TMR-JWAP Senior Member

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    This is something new to me: Since you cooked the system it will require a flush and replace of Inverter coolant.
    The inverter does a pretty good job of protecting itself from overtemperature conditions and I've yet to see cooked coolant, but maybe others have seen burned water. When we're talking about an over temp inverter, we're not talking about boiling hot or fluid loss due to pressure release. The portion of the pump that burns up is the electronics on the outside of the pump, mounted on the bottom and covered with rubberish potting material. This has no chance of contaminating the coolant.

    Just squeeze the hoses closed using some medium hose clamp pliers, pop the hoses off the pump, replace the pump, reinstall hoses, remove the clamps, add a couple ounces of fluid to the reservoir while running and venting the pump.
     
  14. ryguy

    ryguy Junior Member

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    So after way more effort than every video I've ever seen do it, I finally got the new one in. I'm just so bad at this it's honestly pathetic. Example, I let the clamps off of one of the hoses before both hoses were on the pump and I have no clue why I even did this. I guess I thought somehow the coolant wouldn't just flow out of the other side of the pump. I honestly don't know. Almost all of the coolant spilled out. Do I now have to additionally bleed the system? I stopped right there before I messed things up even worse. Everything's all put together but the coolant is all the way to the bottom of the tank. If I do have to bleed the system, is there a video or anything on that or is it simple to do? Because, clearly, even simple things when it comes to cars are hard for me.

    Also, it is harmful to get coolant on open wounds? Because my hands were bleeding from about 3 different places and got drenched in coolant. lol
     
  15. ryguy

    ryguy Junior Member

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    I found a good video on bleeding it in case it helps anyone reading this thread later on: