Check Hybrid System with code P261B

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by WolfpackBill, Mar 27, 2017.

  1. WolfpackBill

    WolfpackBill Active Member

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    So yesterday my wife and I were driving 79mph on cruise control maybe an hour and 15 minutes into our 1 hr 45 minutes trip home and all of a sudden the orange triangle and the "Check Hybrid System" message popped up on the dash. The cruise control as abruptly disengaged and I have lost control of the gas pedal but fortunately the traffic was light enough for me to pull over and see what was going on. My ScanGauge showed a code P261B so I immediately Googled the code and it pointed to a water pump failure.

    So I turned the car off and restarted the car and reset the code. The gas pedal function returned and I was able to drive away and stared at the ScanGauge making sure the engine did not overheat. Fortunately the light never returned and temperature stayed anywhere between 190 and 200 degrees the rest of the way home. When I got home, I opened the hood and checked all the fluids and they were all in good shape and at the right level.

    The morning, I took the car out for a drive around the block and made sure everything was working fine and it was. The orange triangle never returned, no codes nor pending codes from ScanGauge. engine temp warmed up to 190 and stayed anywhere between 185 and 195 for my 10-minute drive around the block. The car acted like nothing happened.

    Here's my question, was this a fluke and that's it or is it a sign to come? My car has 107,000 miles on the clock.
     
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  2. bisco

    bisco cookie crumbler

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    maybe an inverter pump problem? did the '10's get a recall?
    i wonder what would happen if you replicated the original circumstances.
     
  3. Mendel Leisk

    Mendel Leisk Sand Pounder

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    As far as I know there's no recall for 3rd gen coolant pump, engine or inverter. The inverter recall was reprogramming the acceleration response, with aim to protect the circuitry.
     
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  4. m.wynn

    m.wynn Senior Member

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    Thanks for reporting this. Water pump integrity is a big question mark in my mind with regard to the trending gen 3 head gasket failure issues we're seeing reported here. For this reason, I personally would change that pump out without hesitation, especially if you haven't yet done the ~100k engine coolant drain/refill. Great time to kill 2 birds...

    The pump trends at ~$250-$275 on eBay for the OEM Aisin WPT-190. I have one here that I will be changing out preemptively once the winter weather backs off.

    To clarify, P261b is an engine water pump code, not inverter.
     
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  5. bisco

    bisco cookie crumbler

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    is there no overheating temp dummy light on the dash?
     
  6. m.wynn

    m.wynn Senior Member

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    There is, but knowing what we know, I'd never want to see it. It's hard to think these heads have integrity enough to tolerate an actual overheat.
     
  7. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Yeah there's that at least, but no temp gauge. For that you need something like Pontiac Sunfire...

    Page 500 of Owner's Manual:

    upload_2017-3-27_6-27-5.png
    upload_2017-3-27_6-30-36.png

    A few pages of emergency procedures info, starting on circled page, saying too it could be one or the other circuit with the problem.
     
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  8. bisco

    bisco cookie crumbler

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    so what was happening, is the car basically shutting down a self protection mechanism?
     
  9. m.wynn

    m.wynn Senior Member

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    Hard to know. The "check hybrid system" warning would typically bring on limp mode but the OP only reports the engine related code. Assuming ScanGauge is hybrid code aware, I'd expect to see a hybrid code thrown, but who knows what P261b protocol may be in protecting the car. So I'd address the P261b with somewhat of an expectation that the "check hybrid" behavior would be cleared simultaneously or would then need further investigation.

    You guys well know my paranoia about these engines. This is an incident I'd take seriously rather than reset and forget.
     
    #9 m.wynn, Mar 27, 2017
    Last edited: Mar 27, 2017
  10. Mendel Leisk

    Mendel Leisk Sand Pounder

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    US schedule is engine coolant at 100K miles (or 10 years), and inverter coolant at 150K miles (or 15 years). Has the engine coolant been changed?

    ( It wouldn't hurt to do both at the same time though. The Canadian schedule make no distinction, says change both at 160K km's (or 10 years).)
     

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  11. m.wynn

    m.wynn Senior Member

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  12. WolfpackBill

    WolfpackBill Active Member

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    Thanks for all the responses!! The engine coolant was replaced at 99k when they replaced my timing chain cover gasket.

    I really don't know what happened to it. I was driving, the yellow triangle light came on, "Check Hybrid System" message popped up and the gas pedal has no response whatsoever. Air conditioning was working fine, actually, everything was working fine after I restarted the car. It was the weirdest thing!

    I drove the car as I usually do today (over 100 miles around town) as I have a day off today and not once any of the lights popped up nor any error messages. I just got home and hooked up Tech Stream and it has no error codes. I'm starting to think it really was a fluke.
     
  13. Boffin

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    My 2010 did this to me as well. I limped the car into a dealer, who kindly diagnosed my problem, and then, as I needed to get somewhere, reset the codes for me. No charge! I managed another couple of trouble free months, and it happened again. This time I replaced the water pump!

    I'd look into replacing that pump!
     
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  14. WolfpackBill

    WolfpackBill Active Member

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    If that's the case, I'd better have some money set aside for that then. How much did it cost for you to have it replaced?
     
  15. Boffin

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    I had it done by Toyota. They wanted $1200, but as the car then had only 62,000 miles on it and was just out of warranty, I talked them down to $600. Still expensive!! If you can find a good manual (I couldn't find one, but knowing what to do is critical), and you know a little about working on cars, you can buy a new pump at Rock auto for $177 - $250 and install it yourself. Make sure to change your coolant at the same time (~$20 - $40). Also plan to spend most of a Saturday doing it.
     
  16. m.wynn

    m.wynn Senior Member

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    Don't hesitate to do the work yourself. Drain the coolant, pull the air intake and the pump is right there, albeit a bit of a tight squeeze working quarters. Refill and bleed of the coolant loop is easy on Gen 3, too. I'll be doing mine soon, so if I beat you to it I'll post my experience. I'll re-stress what I feel is the importance of going with the OEM, Aisin pump. I'd be sketched by one of the cheaper options in this important application.

    As it turns out, there was a TSB for P261B back in the early days of the 2010. Would be interesting to see if your VIN was yay or nay...
     

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  17. Raytheeagle

    Raytheeagle Senior Member

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    When do you plan on doing the pump changeout?

    I have an east coast trip planned April 26- May 1 to the northern part of PA where my parents live. Might be looking for a "get away day" (y).
     
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  18. WolfpackBill

    WolfpackBill Active Member

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    Thanks for the PDF's! My VIN is after the indicated range so my car does not apply. I just got mine (Aisin pump) delivered to my doorstep yesterday and I bought a bottle of coolant today so I can tackle this tomorrow. I will let you know.
     
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  19. WolfpackBill

    WolfpackBill Active Member

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    So I replaced the water pump today. It was extremely easy to get to. I spent more time underneath the car to remove the under engine cover to drain out the coolant (which I fount out there're cutouts for the coolant drain and the thumbscrew at the radiator, left side of it, btw). There are 5 bolts to unbolt. Make sure you have a 12mm deep socket or a socket with extensions and a box wrench (I have the ratcheting kind). Once you those bolts out, take it out and put the new one in. Took me 2 hours, including time for the coolant to cool down. Not a bad project at all!
     
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  20. Boffin

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    Billy,

    Well done! I only wish I had known about this site, with its knowledgeable owners, before I had turned Toyota loose on mine. It would have saved me $350.00.
     
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