1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Gen 1 Prius temporarily loses power while driving

Discussion in 'Generation 1 Prius Discussion' started by mr23, Mar 2, 2016.

  1. mr23

    mr23 Junior Member

    Joined:
    Aug 11, 2007
    9
    0
    0
    This just recently started happening just shy of 200k miles, 14 years.

    While driving down the road, suddenly notice a power loss or no power, ie, no motor output. Sometimes the just the ICE won't accelerate, sometimes it's both ICE and Electric motive force. When this occurs, the Brake and ABS check lights turn on. After a few seconds, to 10's of seconds, then the motive power reenables and the Brake/ABS lights go out. Often the cars continues on with no repeat. Testing over a few drives, it seemed to only do it during the warmup cycle when coolant was near 160-170. However on a drive in the afternoon after it occurred in the morning; with ambient around 30 degrees, windows cracked, interior heat off, it didn't occur on the 15 minute drive, mostly freeway speed, even after about 10 minutes and cranking interior heat on. No codes are registered when this happens. I used Torque Pro and monitored things like throttle position and such, and things there seemed normal. Eng rpm dropped under 1000rpm and wasn't steady. Watching the MFG the power flows responded to the throttle (pushed/released) as if the engine was still doing what was asked (go figure, the display shows what is commanded, not what is occurring?).

    A few times (2 of say 10 tests), the PS light comes on, it is more persistently 'dead', when it does 'come back', it isn't 'reliable' or faultless for the rest of the drive.

    Haven't checked for rodent damage (possible). Haven't tried the blow-out-the-tin-whiskers on the throttle position pot. Neither seems likely as some trips it will run normally, with no problem occurring. Wondering if a PCB has a component failing. 12V isn't dead, the DC-DC is supplying 14V. The 12V may be dropping below 12 when starting, but it always starts and runs fine for the next say 5-10 minutes.

    Has anyone seen this before? I tried searching web and forums, but there a lot out there on ABS/braking etc and didn't find my exact problem.

    2002 Prius.

    Bought a used Leaf, so it isn't urgent. Would like to fix it, unless the repair is too costly.

    If it's an expensive repair, anyone need parts? ;-)
     
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,932
    15,553
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    "No codes are registered" on an issue like this means you are not using a reader capable of reading Gen 1 Prius codes. You might be able to load a Gen 1 vehicle def into Torque ... if you already have, it might be helpful to indicate where the file came from.

    It is increasingly common for people to use Mini VCI and a laptop to read their codes.

    The diagnostic information would be very helpful for getting to the bottom of this.

    Regards,
    -Chap
     
    bwilson4web likes this.
  3. mr23

    mr23 Junior Member

    Joined:
    Aug 11, 2007
    9
    0
    0
    Ah thanks. I recently switched phones and hadn't remembered to transfer the Torque file. I'll try again this weekend

    Do you have a reference for that?
    I've used this one for a couple of years, and it was not installed during the first event. I'll check for codes, remove it, disconnect 12v, reapply, then test drive and try to reproduce. I might do that while it is still cold out.
     
    #3 mr23, Mar 2, 2016
    Last edited by a moderator: Mar 2, 2016
  4. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

    Joined:
    Jul 29, 2011
    3,159
    989
    0
    Location:
    Tucson, AZ
    Vehicle:
    2005 Prius
    Model:
    Four
    This sounds like a faulty wheel sensor to me. One that's intermittently faulty. When this happens, it will give the symptoms you state because the computer doesn't know what to do when it sees a zero input on one wheel.
     
    bwilson4web likes this.
  5. LEVE

    LEVE Member

    Joined:
    Jan 15, 2010
    191
    97
    0
    Location:
    On the Willapa
    Vehicle:
    2005 Prius
    Model:
    N/A
    I also have a Super Mini ELM327 V1.5 Bluetooth OBD2 OBD-II Car Auto Diagnostic Scanner that I use with the Android App Torque on both a phone and a tablet. Much of the time when I hook the ELM327 to the Prius I do get a "ABS" brake light warning. This warning light will stay on until the engine has been restarted after the ELM327 has been removed. On other vehicles the ELM327 works fine. This is also the case for both my 2002 and 2005 Prius. I still keep it in the car to help anyone out along the side of the road, as needed.

    I have the Scanuage 2 and it works well for basic items. I'm too lazy to program for some Prius aware items.

    I have a two MiniVic systems, but haven't used them as yet... I've not needed to hook one up to one of my ancient laptops that I've dedicated to this chore. But, they are in the garage when I am inclined to hook it up.

    My Go-to scanner is a Denso Handheld Toyota Intelligent II Scanner, It's not cheap, about $325 on Ebay. But it tells me everything I need to know about my 2002 and my 2005 Prii. This is in the the car when ever I am traveling any distances.
     
  6. MDNHW11

    MDNHW11 Junior Member

    Joined:
    Nov 8, 2015
    54
    25
    0
    Location:
    Canada
    Vehicle:
    2001 Prius
    Model:
    N/A
    Mark me as someone who has also had ELM327 issues with my Gen1 Prius. Steering issues in my case.
     
  7. mr23

    mr23 Junior Member

    Joined:
    Aug 11, 2007
    9
    0
    0
    We've also have a slight overfill of oil. Time to also check the throttle body, intake, etc. Glad it is warming up nicely this weekend. Good opportunity to train up the youngest son.
     
  8. bwilson4web

    bwilson4web BMW i3 and Model 3

    Joined:
    Nov 25, 2005
    27,390
    15,518
    0
    Location:
    Huntsville AL
    Vehicle:
    2018 Tesla Model 3
    Model:
    Prime Plus
    Which ECUs does it report?

    Can you get a traction battery, module-pair, voltage list?

    Thanks,
    Bob Wilson