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Check hybrid system, p0a94, still drives?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Stevedk, May 3, 2020.

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  1. Stevedk

    Stevedk New Member

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    Mystery: 2010, 174k, symptom: weak acceleration, alerts: "check bybrid system" and yellow triangle. I checked codes: 2 codes: p0a94, inverter, and, p0401, exhaust. Mystery is that vehicle starts, runs, and accelerates from stop, just less power than it should have. It does operate "normally" other than weak acceleration- I was able to accelerate on freeway ramp and drove it home 10 miles at 60-65 mph. I'm seeing others say they are stuck in limp mode. I can't say for sure, but it seems that only the gas engine is operating. Power mode does not seem to engage. Hope thats enough info! One other bit of info: car has dealer installed after market remote start.
     
    #1 Stevedk, May 3, 2020
    Last edited: May 3, 2020
  2. pjksr02

    pjksr02 Active Member

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    Lucky you were able to get home.

    Have you had all your warranty repairs completed, especially the "Intelligent power module?"

    The P0401 could be unrelated to the hybrid problem. Have you ever had the EGR system cleaned? If you're new here, look around the many threads about the EGR system.
     
  3. bisco

    bisco cookie crumbler

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    what are you reading the codes with?
     
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  4. Stevedk

    Stevedk New Member

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    I've got two basic code readers. Actron auto scanner. Cp9575. Spx Corp. And, hypertough ht309. This morning, I pushed start button. the car immediately started up with gas engine and proceeded to idle. I drove it around briefly. The engine stays on. Does not shut down at stops. While I can accelerate, up to hiway speed, the engine/ transmission does race a bit if I push down on gas to hard, which makes sense since my electric motor is not operating and you have the constant velocity transmission. I have not at this point tried resetting the codes to clear them which I could do with these scanners nor have I tried replacing the 12 volt battery which I've seen in some threads helped another owner.
     
  5. Stevedk

    Stevedk New Member

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    Thank you. This is a recent purchase so I have not looked into the warranty repair history. Will do that. Thanks. I see that there are some manufacturers warranties that cover certain hybrid syste issues up to 150k so that doesn't help me at 174 k. I own a 2005, and another 2010, so I'm very familiar with how the car "should" act when things are normal. I see that a previous owner of this 2010 had a P0A2D code caused by corrosion in "DA1." This morning I started it up, the gas engine immediately started and idled. I drove it around the block. It did race a bit, if I have it too much gas pedal, but came up to speed. The electric motor did not come on at any time. At stops, the gas engine stayed on at idle
     
  6. bisco

    bisco cookie crumbler

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    always good to test the 12v health. auto parts stores do it for free. you need tech stream for the codes, or at least something like torque pro.

    what is the level of the hybrid battery on the dash?
     
  7. Stevedk

    Stevedk New Member

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    Here is an update: I disconnected the 12V battery, and then reconnected to see if that would eliminate the condition. It did! except not the way I wanted. After reconnecting, the former condition, of being able to drive with just the gas engine, no electric, now it simply will not start. Evidently, the former owner was able to put the system into aa sort of limp mode that allowed it to operate with just the gas engine.
     
  8. Mpdcnva

    Mpdcnva Member

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    While getting onto the interstate I punched the accelerator and the car beeped, all lights came on and I lost all power. Took my 2010, 198,000 miles to the dealership with a P0A94, P0C3A, C1259 and C1310. Just picked it up, fully covered by the 15 year unlimited mileage warranty for IPM failure. But the service advisor laughed and said the inverter case was the only thing NOT replaced. The bill was itemized at $2800. Thank you Toyota. I had no issues, they said it was bad and it was fixed. Car is zippier now and a couple weird things have stopped.

    don’t waste your time getting a replacement if Toyota is going to fix it for free.
     
  9. ChapmanF

    ChapmanF Senior Member

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    Sometimes the old one will go in especially dramatic fashion, and mess up the case right here:

    [​IMG]

    If that happens, you get a shiny new case too! :) But I guess you didn't hit that particular jackpot.
     
  10. Mpdcnva

    Mpdcnva Member

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    The service order said…..
    Computer sub-a. $290.00
    Transistor kit. $1676.99
    Seal packing. $121.99
    Plug kit inverter D. $53.99
    Gasket. $4.99
    Seal, masking. $127.99
    Grease x 23 7884 4. $133.98
    Super long life cool $20.24

    Labor. $357.00
     
  11. Mpdcnva

    Mpdcnva Member

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    The funnier part, it’s covered till 2024.
     
  12. Mpdcnva

    Mpdcnva Member

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    Considering I was about to get one from a junk yard, but thanks to techstream, google and this site? I’ll take this jackpot. GEN3 PEOPLE NEED TO KNOW, IN 2021, TOYOTA IS HONORING THIS FAILURE.
     
    #12 Mpdcnva, Aug 26, 2021
    Last edited: Aug 26, 2021
  13. ChapmanF

    ChapmanF Senior Member

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    I see from your list, you also didn't need the converter. That would've been another $586.94 ... billed to Toyota, of course.

    ... which is weird, because the converter was the one of those components I would have suspected most, based on the reported codes. :confused:

    I wonder if they always bill Toyota for a whole tube of seal packing or thermal grease, every time they do one job....
     
    #13 ChapmanF, Aug 26, 2021
    Last edited: Aug 26, 2021
  14. Mpdcnva

    Mpdcnva Member

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    My brother works for Honda and they bill a tube per job. I used the Hondabond HT where necessary, when I did the head gasket. Good stuff.

    Now the strange part. My mileage jumped big time. I gained 10 mpg. I drive my car; and have always gotten 42 (lead foot). I have always beaten my Prius’ (4th Prius) with my foot and every one has taken the beating. Now I am getting 52. Filled it up and the DTE is now 610. Before (old inverter parts) it was 450. It now moves really good; like my gen2; zippy. When I only had 3 bars, EV was not allowed. Now EV works down to 2 bars. In the last 2 months, from a cold start, 6 bars would drop to 2 in under a mile. That has also stopped, battery is now stable. I’m assuming the old parts were shorting out before they finally blew.