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Can you have inverter pump failure without the P0A93 Code?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by priuslyfe, Jul 24, 2023.

  1. priuslyfe

    priuslyfe Member

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    My 2007 287K miles Prius recently had the Red Triangle while driving. Checked the codes and none came back indicating inverter pump failure.

    However upon googling the typical reasons for the Red Triangle I looked at all the fluids, which were OK, and the inverter pump. There was no movement in the reservoir or vibration at the pump.

    Is there some type of "ghost code" whereby it doesn't show P0A93 despite being a problem with the inverter cooling system? Would like to know before I try to replace? Is it worth buying an OEM or should I go for the Amazon clones that cost $25?

    Thanks for any advice.
     
  2. Brian1954

    Brian1954 Active Member

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    What codes did you find?

    What are you using for a scan tool? Most generic scan tools can not communicate with the 12 or more ECUs in your Prius.

    Do not buy an inverter water pump until you have a compatible scan tool that can read all the trouble codes. If you do plan on replacing the inverter water pump, only buy OEM, they last much longer than a cheap generic pump.


    Posted via the PriusChat mobile app.
     
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  3. PriusCamper

    PriusCamper Senior Member

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    You can have a failed inverter pump with no PA093 error code up until you get dash warning lights and then that error code is stored and if you aren't seeing it, that's either a problem with the app your using or a problem with your OBD2. Please let us know which app you're using and which OBD2?
     
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  4. priuslyfe

    priuslyfe Member

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    Thanks for your advice.

    I used the exclusive NAPA AUTO PARTS code reader! Basically, the one they loaned for me to use in the parking lot. The only code that came back was for the oxygen sensor which seems to trigger whenever a replaced catalytic converter is used (which I have as well).

    What is a good code reader to buy or is there an app for that? I have heard of Dr. Prius but thought it was only for HV battery issues.

    Any suggestions which OBD reader to buy?
     
  5. PriusCamper

    PriusCamper Senior Member

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    That code reader is probably ancient and clearly isn't programmed for hybrid car specific codes. A basic OBD2 code reader that connects to your phone so you can run apps like Dr. Prius costs less than $20 and can save you a fortune in towing fees and a ruined day if you keep it in your glove box. Here's buyer's guide: Hybrid battery diagnostic and repair tool for Toyota and Lexus
     
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  6. Brian1954

    Brian1954 Active Member

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  7. Tombukt2

    Tombukt2 Senior Member

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    02 code for a aftermarket cat ? P0420. ? That's cat below threshold code
     
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  8. ChapmanF

    ChapmanF Senior Member

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    The answer to the title question is yes; P0A93 isn't set by any specific pump problem detection, but by noticing the electronics getting too hot (say, because the pump isn't moving the coolant). So yes, it's possible to have the pump fail, but be driving lightly loaded in mild weather and not have any detected overheating, and there won't be a P0A93.

    But with no problem detected, there wouldn't be the warning triangle either. Since the triangle showed up, there are trouble codes.

    You said "Checked the codes and none came back indicating inverter pump failure." Does that mean some codes came back? What were they?

    There are a couple hundred codes that can make the triangle come on; pump failure ain't the only game in town. If you're not seeing any codes from the power management control ECU (the one responsible for the triangle light), it's probably a matter of using a scan tool that isn't seeing them.
     
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  9. priuslyfe

    priuslyfe Member

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    UPDATE:

    Used a friends bluetooth OBD2 scanner which is a good one and listed on the website reviewing them. Downloaded an app called "Car Scanner ELM OBD2" which was free with ads. AGAIN..the only code that came up is the P0037 which is for the oxygen sensor. Same result as the less fancy NAPA code reader.

    However, when I actually look at the pink coolant inside the reservoir next to the inverter. It does NOT MOVE. I've used a flashlight as well. Sometimes it vibrates because the engine is revving but otherwise when the car is "ready and on" it doesn't move.

    I'm just going to go ahead and replace it regardless. Gonna go to a dealership tomorrow and buy the inverter pump.
     
    #9 priuslyfe, Jul 24, 2023
    Last edited: Jul 24, 2023
  10. Tombukt2

    Tombukt2 Senior Member

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    Did you check the AM2 fuse and the fuse box just above and behind the inverter pump behind the headlight Is that fuse burned replace it now see if you hear your pump and see things moving but you want to find out why that fuse blue the inverter pump could be getting old and tired and starting to draw too much current blowing the fuse.
     
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  11. priuslyfe

    priuslyfe Member

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    coincidentally, I specifically drove to a nearby gas station to check that AM2 fuse (under their business lights) and just returned after reading about it here. Pulled it out when the car was running (again checking for turbulence in reservoir...none btw); the fuse was in good condition and not damaged or blackened.

    Do you know of any other symptoms of a failed inverter other than the turbulence? I've looked at various sites and they mention either that or codes associated with this. Does the inverter affect any functions inside the car that would be apparent? I read another priuschat thread about the AC not working properly but mine seems to be fine.

    btw: coincidentally here is a thread about why it is NOT a good idea to buy a counterfeit aftermarket inverter pump. Very appealing since Amazon could get it to me tomorrow for under $30. Not gonna bite though.

    Counterfeit vs Real OEM Toyota Prius Inverter Pump 04000-32528 | PriusChat
     
  12. Tombukt2

    Tombukt2 Senior Member

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    Your air conditioner can cut out when the inverter pump is not working and temperatures are starting to get a little high I guess the system throttles back power hungry items like air conditioning stuff like that then it'll start charging the battery to a lesser degree when it gets extremely warm and then I guess after that you could start burning components up in the inverter I guess it will shut the car off when the inverter and associated electronics get hot enough to put this in perspective I drove around for 4 days without an inverter pump all local but still doing my 120 mi almost a day and if I'm not mistaken it was summertime above 85° without driving on the highway and driving like a sane individual pretty much every stop I'd get out and feel my inverter hose and related hoses and they were maybe 118 1:15 somewhere in there never set off any lights in my air conditioner never cut off but I was able to make my air conditioner cut off after I got the pump in and was still experimenting around I was able to make my air conditioner stop working by getting the temp up enough. The pancake type pumps that are used for this inverter setup are seemingly starting to have problems It's manufacturing thing it looks like I don't know if it's Asian's problem or other people making them It seems to me it's a very simple pump you'd have to try to deliberately screw something up to mess it up like the circuit board or the plug that burns up I mean I don't know how you do that make it out of to thin material or something.
     
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  13. Tombukt2

    Tombukt2 Senior Member

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    Now just unplug the inverter pump leave the bracket in the car and just undo the gold bolts that hold the black pump to the gold bracket withdraw all the pump and install the new one the exact opposite take it off the bracket and put the new gold bolts and the new pump on your old bracket It's a lot easier look at the socket on the pump and see if you see any burn marks on any of the pins.
     
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  14. priuslyfe

    priuslyfe Member

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    thank you.

    I've done it before but remember having not the easiest time doing it. I'm kinda apprehensive to do it because I've never been good at bleeding brakes or coolant.
     
  15. mr_guy_mann

    mr_guy_mann Senior Member

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    The inverter coolant pump does just that- moves coolant through the system to carry heat from the inverter and transaxle to be "dumped" by the radiator.

    If the inverter gets too warm, it will disable the A/C compressor, then probably begin to limit drive function before setting the overheat code and disabling the car.

    Posted via the PriusChat mobile app.
     
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  16. priuslyfe

    priuslyfe Member

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    Whew!

    I thought it went from RED TRIANGLE to dead. So there is a systematic downward use of power until it dies. Just want to be able to make it to the dealership and back tomorrow. Plan on going in the early morning as to avoid the midday heat (around 90 F).
     
  17. priuslyfe

    priuslyfe Member

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    UPDATE:

    Earlier, after clearing all the codes, I drove the Prius in 90 degree weather with the AC on full-blast some distance. At first the car dashboard looked fine and after about 20 minutes of drivin then the RED TRIANGLE appeared. Checked the inverter reservoir and no turbulence. I think initially I was looking for even the slightest movement in the fluid to AVOID having to replace the pump. However it needs to be noticeably and vigourously moving fluid (turbulent).

    Then I replaced inverter pump today. to bleed basically I left the car running, AC on, and both radiator cap & reservoir cap off to de-gas the system. Hopefully thats enough. Red triangle gone after being reset and letting the car run for 30 minutes. Healthy swirling turbulence in inverter reservoir tank now.

    Ran diagnostic codes with OBD2 app and bluetooth a number of times ...again only the P0037 oxygen sensor code. Not sure if this is the end of it though.

    Just wanted to let others know that I never had the 093 code associated with a faulty inverter coolant pump. Best to check it regularly.

    thanks again all.
     
    #17 priuslyfe, Jul 25, 2023
    Last edited: Jul 25, 2023
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  18. bisco

    bisco cookie crumbler

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    but you never used a prius compatible scanner?
     
  19. priuslyfe

    priuslyfe Member

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    I just wanted to get it done as quick as possible so I got what I could quickly, but now I'll delve into the the specifics.

    So far everything looks good but it looks like the Autel MAXI AP200 is the one to get, which is around $60. I read a review link and thought it would be sufficient but re-reading that thread...

    "FORGET (almost) EVERYTHING THAT I POSTED ABOVE! Stop what you are doing and go purchase the Autel MAXI AP200. NOW. This device (proprietary OBD2 Bluetooth adapter) and app are everything that ALL the other apps are not. It's about 65% of the functionality of a Techstream"

    Gen2 OBD2 app review | PriusChat
     
    #19 priuslyfe, Jul 26, 2023
    Last edited: Jul 26, 2023
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