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PCS and Hybrid System Warning Message

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by Frank Perkins, Aug 8, 2014.

  1. Frank Perkins

    Frank Perkins Member

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    I'm hoping I could get some insight from the community.

    First time it happened I was driving up a pretty steady incline at about 75% EV power and the Check Hybrid System, pull over safely message came up. I pulled over and everything looked ok. Truthfully, how the hell do you "check a hybrid system"? I scheduled a service appt but then the next morning the message went away. It should be noted that this incline was really just a hill... nothing crazy and I was going about 35mph

    A few days ago, I was driving up the same hill, same thing happened. Except this time it also said Check PCS system.

    I brought the car to Colonial Toyota this morning, but the message had already disappeared. They said they did not find any stored codes in the system and it might have been the radar collision avoidance system being triggered. That didn't make much sense since there was nobody in front of me.

    I found this recall notice, but my VIN does not come up on the recall list: https://techinfo.toyota.com/techInfoPortal/staticcontent/en/techinfo/html/prelogin/docs/cp/e0etofaq.pdf

    I know Toyota has had some issues with brakes/etc, should I be worried? Truthfully, I didn't expect the dealer to do be of much help.
     
  2. bisco

    bisco cookie crumbler

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    sounds like a tough one with no codes, hopefully someone with an advanced has insight. have you gone up similar hills without warning? did it happen in the same place?
     
  3. Frank Perkins

    Frank Perkins Member

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    It happened on the same hill so I'm assuming something triggered some "stress" on the EV system and it went into failsafe mode and turned the engine on. I actually have an OB reader, but I'm not sure how to use it read the codes if this happens again. It might be something I research.
     
  4. bisco

    bisco cookie crumbler

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    if it logged a code, it would still have been there when you took it to the dealer.
     
  5. bisco

    bisco cookie crumbler

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    any idea how many ev miles left when it happened?
     
  6. Frank Perkins

    Frank Perkins Member

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  7. Chazz8

    Chazz8 Gadget Lover

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    Here is a quick and easy thing to check that could explain everything;
    Check for obstruction of the battery cooling vent near the rear passenger door. If someone or something is blocking the vent, the fan can't blow enough air over the batteries and they can overheat and tell/make you check hybrid system.

    Some error codes are only accessible using TechStream (Toyota software), but I'm curious why they could not find any codes to tell us what to check in the hybrid system.

    Good luck.
     
  8. bfd

    bfd Plug-In Perpetuator

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    A couple of ideas for you:

    First, your description fits almost exactly what happened to me back in December. The local shop wasn't immediately able to locate the problem either. Apparently, the code was not one they'd seen before so they almost ignored it, but they made contact with the factory anyway and they were able to diagnose what happened over the phone. I know the tech personally, so I believe his story - especially the part about not having ever seen the code before and almost dismissing it.

    Turned out to be a blown heat sensor in the inverter - the fix was to replace the entire inverter. It took about 10 days all told to get the part in and installed - Holidays, etc. and get back on the road. While no one could say what caused the blown sensor - or how to avoid the problem in the future, we speculated that the uphill run in EV could've put some extra heat into the system which blew an already unstable sensor. Probably was going to happen sooner or later regardless of the situation.

    Moral to the story: Keep your eye on this.

    Secondly, about 3 months ago, a similar triangle and check PCS system fault came up again. Turned out that I had a ScanGauge II plugged in at the OBD-II connector and it was sending random signal through the system. Apparently Toyota sends signal and power for other systems through their OBD-II connector. The fix for that was that the ScanGauge folks sent a 'read-only' wire with a few pins missing.

    Neither of the problems have returned so far.
     
    #8 bfd, Aug 12, 2014
    Last edited: Aug 12, 2014