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Check Hybrid System, P0A0F / P2111

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by shawn.ne, Jun 16, 2022.

  1. shawn.ne

    shawn.ne Junior Member

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    2013 PIP, 191k

    “Check Hybrid System” appeared while driving. I didn’t realize the engine wasn’t running or starting. Consequently, the HV battery ran down and the car shut off in Neutral and I had enough momentum to pull over. Had it towed home where it sits now.


    Techstream shows P0A0F and P2111, 206 code for the former in the FF data.

    Full explanation for P2111 says “Throttle Actuator Control System - Stuck Open”.


    Reading related threads, my issue seems different to what other people have encountered. I enjoy learning about my [fourth] Prius, but I don’t think I’ll be able to solve this myself unless it’s something simple. I change the plugs and do oil changes and transaxle fluid changes, but not too much beyond that. Is there anyone in the Boston area that you guys trust or can recommend?
     
  2. Potorap

    Potorap Active Member

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    Hello Shawn,

    I had similar experience with my 2013 PIP. It ended up being Brake actuator $2k at dealership.
     
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  3. shawn.ne

    shawn.ne Junior Member

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    Thanks for that, Potorap.

    I'm thinking that my issue is not actually specific to the Plug-In, and maybe more people will see it if it's in the Gen III section? Should I delete and repost? Or maybe a moderator can move it?
     
  4. bisco

    bisco cookie crumbler

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    how many miles on her? try cleaning the throttle body.

    report your post and ask them to move
     
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  5. shawn.ne

    shawn.ne Junior Member

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    About 191,000 miles. I guess there are videos for cleaning the throttle body? I don't think I have ever worked on that part of the car. Since you're in Boston, maybe you can recommend someone to work on it in case I'm not able to clear up the problem? Given the P2111 DTC it does seem to be fairly likely the throttle body and not something like a hybrid system component failure, right?
     
  6. bisco

    bisco cookie crumbler

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    i have never seen nor found a good hybrid shoppe in these parts. but any decent mech could do it, it's not fancy.
    check out @NutzAboutBolts youtube channel, he should have something.
     
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  7. Tideland Prius

    Tideland Prius Moderator of the North
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    *OP requested move to Gen 3 section*
     
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  8. Eddie25

    Eddie25 Active Member

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    You could visually make sure that the throttle is not actually stuck open, you can get to it in no time if you follow instructions on how to clean the intake manifold (only up to that point).

    Then I would use Torque or similar app to make sure that the ECU is reading the throttle position correctly.
     
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  9. shawn.ne

    shawn.ne Junior Member

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    After getting to the throttle plate I discovered there's fluid in there. Like kind of a lot. I took some photos, but they're not great. It looks to my untrained eye like more than what could result from condensation alone. My question is: How does a substantial amount of fluid even get in there?? Has anyone ever seen or heard of that happening?
     
  10. ASRDogman

    ASRDogman Senior Member

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    Because oil is circulated back through the intake to be burned.
    It comes through the pcv valve. That's why people put oil catch cans on....
    Spray it with carb cleaner and make sure it's shiny clean.
     
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  11. Eddie25

    Eddie25 Active Member

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    Yes, most people who've ever looked at their throttle body have seen this exact thing. Personally I wouldn't worry about it much at the moment, besides maybe cleaning it up a little. I could be wrong, but I doubt this is your issue with the code. Is the throttle plate clean and is it sitting normally?
     
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  12. shawn.ne

    shawn.ne Junior Member

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    Yes, the throttle plate is reasonably clean. I didn't have carb or throttle body cleaner so I just used a paper towel with some alcohol on it. I have cleaners, but they're over 100 miles away. I'll buy some more and go over it again.
    What should my next step be? You mentioned making sure the ECU is reading the throttle position correctly. I have the VCI cable/techstream. What should I look for exactly?
     
  13. Eddie25

    Eddie25 Active Member

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    Like I said, If it were me I'd be looking at the throttle reading in the Torque android app, just to get more data. I'm sure Techstream can do it, but I don't currently have access to that. I'm far from an expert just trying to give the easy checks. From what I gather the computer thinks your throttle is stuck open, if it's not then I'd assume the most likely culprit is the throttle position sensor (which is built into the throttle assembly I think). I did find one throttle check for my car which involves reading the resistance between two pins on the connector (assuming this checks the TPS), but I'd advise you check your own repair manual for your car because I'm not familiar with the plug-in and I don't want to steer you in the wrong direction.
     
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    This "may" be a problem once the other stuff is sorted. With second gen the hybrid battery would run right down, requiring dealership intervention to (hopefully) recharge, but IIRC with third gen they revised the programming to shut things down sooner. Hopefully.
     
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  15. shawn.ne

    shawn.ne Junior Member

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    I had the car towed to a dealership and they found the codes I found plus speed sensor codes from the front wheels, I think. I haven't paid them the $170 for diagnosing yet so I don't have the paperwork. They wanted to replace the entire intake manifold and put in new sensors, I guess. I asked the estimate and it was just north of $2k. I said, "Stop right there." Just to clarify, they did not guarantee the work they wanted to do would actually fix the car. Dealerships and me are like Lucy and Charlie Brown with the football.

    When the tow truck came, the engine did start, although haltingly, and ran for about 15 seconds before shutting down with the "Check Hybrid System" message. I was hoping to keep the car going, but I'm ready to pass it off to Carvana or Car Max. But they won't take it unless it's drivable. Should I just bring it to a local independent garage? I'm starting to lose hope that's it an easy-to-solve problem.
     
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  16. Eddie25

    Eddie25 Active Member

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    I looked it up and I'm pretty sure we have the same throttle, so I'll post the inspection test I have. If you cleaned it out you could do this test, you just measure resistance between two points with the harness disconnected. It might be worth a shot. If it's bad, a throttle assembly replacement is a DIY job in my opinion. My guess is that the dealership thinks it's the throttle assembly (tps specifically), which it probably is, and they just want to sell you the whole intake assembly along with it. Can't speak on the speed sensors, but that seems fishy. A good mechanic is your best bet if you are not mechanically inclined, I'd never trust a dealership.
     

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  17. shawn.ne

    shawn.ne Junior Member

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    Thank you very much, Eddie. I'll update.
     
  18. Eddie25

    Eddie25 Active Member

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    Even before the throttle body resistance check you should try to figure out what your throttle % is reading. You can probably do it with techstream. I don't think you can control the throttle with the Key ON Engine Off, but at least you can see where it's at without the pedal depressed. Mine is at around 16%, I would assume a high reading would indicate a bad TPS and make sense that it throws that code, but that's a guess. I did a bit more research on the wiring of the throttle assembly and from what I gather the two connections you test (M+ and M-) are part of the actuator, not the TPS, so maybe that won't tell the whole story, plus a quick check with a computer is easy and no wrenching involved. If you can't figure it out with techstream, get a OBD2 dongle and the Torque (android) app.
     
  19. shawn.ne

    shawn.ne Junior Member

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    I've ordered the OBD dongle.
    I had the car towed from the dealer yesterday, and when I was waiting for the tow truck I started the car AND IT STARTED AND RAN with no Check Hybrid System message and no apparent problem. The tow truck took about an hour so I did this three times over the space of 45 minutes or so. Then when the driver came I told him he could drive the car onto the flatbed, which he did.
    I had it towed to one of the most beloved shops on Yelp in the Boston area. Even if they can't find anything I'm thinking of having them replace the throttle assembly, because like you say the issue seems likely to be somewhere in that component. At a place like PartsGeek the assembly is around 200-250 with shipping. Unless there's a better place to order it from.
     
  20. shawn.ne

    shawn.ne Junior Member

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    Sorry to bump this, but the epilogue is:

    The guys at the independent garage (in Medford, MA) were (and are) really great. They replaced the throttle assembly and throttle position sensor and did a bunch of things they didn't charge for. Prices were: 358 for throttle assembly, 97 for throttle position sensor, 248 for labor. 746 out the door. That was on June 28th. I've now driven almost 6000 miles with no issue. Boo to the dealership all day. Love my 54 mpg average. 196909 miles, heading up to 300 or 400k.