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Trouble running down problem

Discussion in 'Generation 1 Prius Discussion' started by Toygirl, Oct 6, 2021.

  1. Toygirl

    Toygirl New Member

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    I have an 01 First Gen with 295k miles. I’ve owned it 6 years with no problems of any kind until now. Driving normally, triangle comes on, the I lose power. Pedal to the floor, going nowhere. Shut it off, wait 5 minutes and sometimes it runs just fine but the light is still on. Sometimes I can’t get it over 20 mph with my foot to the floor. Drive it 55 miles at 75 the whole way with no problems to my guy I bought it from for diagnostics. 12v was low so replaced it. He pulled these codes; p0171, 0300, 3190, 3191, 3101-204&205. After battery replacement and codes cleared, drove 55 miles back no problem. Next morning, head to work, get 3 miles, triangle is back and can’t go over 20. Codes pulled p0130, p0171, p3190, p3101-204. He suggested cleaning throttle body and replacing plugs. Did that. If one of the codes is showing it’s running lean, thinking the upstream O2 sensor is bad and when the car is cold, runs ok then warms up and starts acting up. I went 10 miles today. Slowed down for traffic then at a light. Took off got up to 30 and then lost power. If I turn it off and let it sit a bit, it cranks right up, triangle still on, and sometimes it acts normal and sometimes can’t get past 20. Turn off sit. Go still 20. Turn off sit. Go it takes off a little slow then gets to speed and acts fine. I’m stumped. I’ve got the sensor coming and it gets replaced Tuesday but wondering if anyone else has experienced this and what it turned out to be. Don’t think it’s the fuel pump. Sensor on gas pedal? Help. Sorry for the long post. First post here as I just joined and trying to be thorough
     
  2. AlexY

    AlexY Member

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    Many possibilities, MAF sensor need cleaning, fuel pump pressure to be checked, injectors. Start with MAF cleaning.
     
  3. dolj

    dolj Senior Member

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    Unmetered air entering from a leaking hose or hose clamp not tightened sufficiently?
     
  4. ChapmanF

    ChapmanF Senior Member

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    My two cents, if the code is right, the mechanic just needs to start going through all the reasons there could be too much air or not enough fuel getting in. They've mostly all been mentioned in this thread already, the rest is just going through them one by one eliminating what isn't the problem.

    If the code is wrong (less common), then of course the mechanic goes one by one through things that could cause a lean-mixture code when the mixture isn't lean.
     
  5. nimblemotors

    nimblemotors Re Member

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    Make sure the 12v battery terminals are good, all kinds of false codes if that happens.
    Just a guess, but if 02 is bad it might give up running open loop after it warms up if the 02 signal is bad.
     
  6. Toygirl

    Toygirl New Member

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    Hi. I just replaced the 12v. We thought it might be throwing some of the codes because it was weak. Connection is good. Having the upstream O2 sensor replaced Tuesday
     
  7. Toygirl

    Toygirl New Member

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    Thank you. I was hoping to find if anyone had experienced this exact problem and figured out what was causing it. I’ll check the MAF and see if it needs cleaned
     
  8. Toygirl

    Toygirl New Member

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    All that has been checked
     
    dolj likes this.
  9. AlexY

    AlexY Member

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    In my case it didn't looked very dirty, cleaning with isopropanol didn't fixed it, just ultrasonic cleaner did the job. Search for MAF cleaning threads, it is quite delicate part.
     
  10. ChapmanF

    ChapmanF Senior Member

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    I can see how you might expect that to be possible when you have this long list of codes like "p0171, 0300, 3190, 3191, 3101-204&205". But really, all those mean are:

    • P0171 - the mixture is (or is sensed as) too lean
    • P0300 - so the engine is misfiring
    • P3190 - and producing less than 20% of expected power
    • P3191 - or failing to start
    • P3101-204 - and the HV ECU got the P3190 message from the ECM
    • P3101-205 - and the HV ECU got the P3191 message from the ECM

    So it really all comes down to the P0171, and there are a lot of things that can cause that. There wouldn't be even any way to know whether anyone has "experienced this exact problem" before finding out what the cause of your P0171 is, and then comparing it to what the cause of their P0171 was.
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    On a side note, and whether this is related or not, who knows.

    I helped a fellow Gen 1 member very recently who had these:

    P0171
    P0300
    P0303
    P0304
    P3191
    P3000
    P3101-205

    He explained he was having some car problems and needed his HV battery rebuilt. He brought it to me, I rebuilt it over the next several days and we met at his home to install it. This is when I found he had been having very similar, if not identical, problems as listed by the OP, then it just completely would no longer even start. I got the above list of codes when I connected my laptop (still have the screenshot photos). After installing the HV battery, we were still unable to get the ICE to start and it would always code out the same.

    Installed new plugs, cleaned the MAF and temp bulb, scrubbed the throttle body interior (toothbrush and TB cleaner), verified every electrical connector possible. Still no start. After several (many) start attempts, we were getting to the point of the HV battery being pretty low. Decided to try some starter fluid. After pressing power button, sprayed the starter fluid into the TB immediately when engine started spinning. We were able to keep it running by spraying in the starter fluid, and it would sputter and try to die if we stopped. Sounded like crap as if it were getting ready to throw a rod. Kind of leads one to believe there's a fuel issue. We let it shut off and sit while we were planning our next move. I was going to remove the HV battery, take it back and charge it and then come back the next weekend, hopefully better armed for these codes. We decided to give it one last try before I took it out. Battery was showing ~20% SOC. on Techstream. He put one shot of starter fluid in the TB, hit the power button and the puppy fired right up. I immediately recognized it sounded normal and had him stop spraying. Sounded normal, ran normal, charged the battery back up over the next several minutes. Engine ran as if nothing had ever been wrong with it. We force charged a bit also and then took it for a test drive. It ran great. This was back in the middle of September. Been running strong with no problems ever since.

    After getting home later that night and doing some research on those codes, I found this TSB information:

    Toyota got their butts kicked on the 2001-2003 trying to figure out why many Gen 1s were getting P3190/3191 and P3101 code.
    They issued a TSB #EG011-03 to help dealers diagnose and repair. This often involved replacing the fuel tank and/or the ecu. TSB photos are below.

    They also recommended a new ECU # 89661-47054 (Toyota's latest revision). I bought one on ebay for less than $20 bucks just in case the problems came back. Still sitting on the shelf.
     

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    #11 TMR-JWAP, Oct 11, 2021
    Last edited: Oct 11, 2021