2005 Prius down after stolen/found- U0100

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by theGlass, Jan 2, 2022.

Page 1 of 2
  1. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    Hi all, some [expletives deleted] stole my prius out of my driveway a month ago. It was recovered a couple of weeks ago, sans catalytic converter, natch. Trying to get it going again, it'll turn on, but the temperature reads "E" and the engine won't start, with an error of U0100, so one of the ECUs isn't talking. I'm suspecting it's the ECU handling the engine, but the thieves didn't even do a good job of rifling through the car for valuables and all the wiring cables seem OK.

    I'm pretty handy with keeping my car going, but I've hit a wall here. Any pearls of wisdom greatly appreciated- either a good way of finding which ECU is the problem ( I was thinking of just unplugging them one at a time and seeing if more than one U0100 comes up) or, failing that, a good referral to a smart prius shop near Oakland California.
     
    #1 theGlass, Jan 2, 2022
  2. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,302
    4,243
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    There should be other OBD2 codes (DTCs) as well. Generally, if there are warning lights on the dash, there a codes (DTCs) being stored in the ECUs. You may need to use a toyota hybrid compatible OBD2 scanner (many will use techstream), what are you currently using?
     
    #2 SFO, Jan 2, 2022
  3. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    I'm using an OBDLink MX+, but with the add on of Prius codes (I think). Let me dig further. Thanks.
     
    #3 theGlass, Jan 2, 2022
  4. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    11,694
    4,732
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    The main concern in relation to ECU after a cat theft is that wires going to the downstream 02 sensor have been cut and can touch ground or touch each other and short-circuit the ECU.
     
    #4 PriusCamper, Jan 2, 2022
  5. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    OK, digging deeper, it says the ECUs not talking are 7E2 and 7E3.
     
    #5 theGlass, Jan 2, 2022
  6. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    Oh that's just great. I guess since that didn't happen with my first cat steal... This is certainly consistent with what I'm seeing.

    Well f it, I'm committed to getting my old horse on the track again. Thanks for the info!
     
    #6 theGlass, Jan 2, 2022
    PriusCamper likes this.
  7. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    11,184
    1,953
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Wire up another O2 sensor and wire it up so it's holding onto the frame not dragging so if you don't have a cat at least the computers will talk you can start the car etc at least they could with mine
     
    #7 Tombukt2, Jan 2, 2022
  8. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    11,694
    4,732
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    It's too late for that because the loose wires already fried the ECU...
     
    #8 PriusCamper, Jan 2, 2022
  9. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    I packed it in for the day, but got the report from the techstream app. I'll give it a good look tomorrow and post. Thanks everyone.
     
    #9 theGlass, Jan 3, 2022
  10. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    Hi folks I looked at the .tse file and it says...things. I'm thinking my first course of action may be to replace the ECU that the O2 sensor was attached to and probably fried? Any guidance muchly appreciated.

    Attached is TSE file. I also spent some quality time removing the unprintable characters, is there an app out there that can parse this file properly? Surely? Thx.

    don't be fooled by the filename extension, I changed it from .TSE to .txt to get it to upload ;)
     

    Attached Files:

    #10 theGlass, Jan 4, 2022
  11. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    OK, looking at the electrical layout, the engine ECU is to the right of the glove compartment. I ripped out that part of the dash and glove compartment and it seems to be no biggie, provided that's the trouble. New engine ECUs look like they go for a bit more than $200 online, not bad.

    Also read a couple of threads here of people's problems after a cat converter theft.

    Also attaching pic of the screen techstream showed with errors. I can read the block voltages of the big battery with my bluetooth/OBD widget just fine, and the car will move under battery power. The one thing that doesn't happen at all is any info or action from the engine, leading me to believe the engine ECU is the first thing to replace/check. My AC has been dead for a while, not worried about that.

    It would suck if the act of cutting that O2 sensor wire fried a few ECUs, but for the moment "they're not all confirmed dead yet"!

    Any wisdom, greatly appreciated.

    IMG_1517.jpeg
     
    #11 theGlass, Jan 5, 2022
  12. TMR-JWAP

    TMR-JWAP Senior Member

    Joined:
    Aug 12, 2016
    6,404
    6,073
    0
    Location:
    Columbia, SC
    Vehicle:
    2007 Prius
    Model:
    Touring
    Assuming that the O2 sensor wires were ripped out instead of a nice clean cut, have you pulled up the front passenger carpet and unplugged the remainder of the sensor harness? That would be top of my list before I did anything else. That plug is under the carpet on the passenger side of the center console.
     
    #12 TMR-JWAP, Jan 5, 2022
  13. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,880
    1,867
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    The connector for the downstream O2 sensor is inside the car- I would find that and unplug it. Then check all the fuses (esp the 15A EFI, 10A ETCS, and 7.5A IGN). Maybe a fuse is popped, maybe the ECM is fried. First you need to have powers and grounds to the computer.

    If those are OK you could get a wiring diagram and confirm all those power feeds (and grounds) are present at the ECM connectors - EFI and ETCS are battery (12V always) and IGN is 12V in "ON/READY".

    You can get a used ECM on ebay- just match up the part number on the case (I think you can use a small mirror to read it without pulling it out). It's plug and play- no programming on a Gen2. Also for testing you can carefully flip the connectors around and plug the replacement ECM in without dismounting the old one.

    Posted via the PriusChat mobile app.
     
    #13 mr_guy_mann, Jan 5, 2022
  14. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,302
    4,243
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Just to the left of either DTC U0100 is a small blue icon, click on that and look for a 3 digit INF (subcode), should be 211, 212 or 530.
     
    #14 SFO, Jan 5, 2022
  15. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    Thanks, mr_guy_man (NJ represent! I grew up in Piscataway) and SFO. Will do all that now.
     
    #15 theGlass, Jan 5, 2022
  16. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    TJR- I'm 90% sure the wires were cut, not ripped out. I'll see if I can find the old one. I already put the new O2 sensor in and plugged it in. First time I had a cat converter stolen, in my driveway, I put in a new one, new sensor and everything worked just fine. This time...not so much.

    Thanks again everybody I'm about to go out and commit repair/diagnostics! Will report.
     
    #16 theGlass, Jan 5, 2022
  17. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    O...MG. The 7.5A IGN fuse was blown. Replaced that, took the car for a 20 min spin, everything works

    DUDE:D

    Can I send you a little token of my appreciation? DM me.

    Thanks to all of you on this thread! What a relief.

     
    #17 theGlass, Jan 5, 2022
  18. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    11,184
    1,953
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Usually it's the simplest crap That's great man
     
    #18 Tombukt2, Jan 5, 2022
  19. SFO

    SFO Senior Member

    Joined:
    Feb 7, 2017
    5,302
    4,243
    0
    Location:
    Northern California
    Vehicle:
    2007 Prius
    Model:
    N/A
    Now that we have that out of the way, how did they steal the vehicle?
     
    #19 SFO, Jan 5, 2022
  20. theGlass

    theGlass Junior Member

    Joined:
    Apr 13, 2016
    22
    3
    0
    Location:
    Oakland CA
    Vehicle:
    2005 Prius
    Model:
    Two
    Oh, it was a perfect storm. somebody left it in the garage overnight without the door closed, dome light drained the battery enough that none of my 12V power supplies could charge it while installed. This was a Monday morning. I left it running in the driveway for a minute to let the car charge it. Got a call from my patent attorney as soon as I went inside, I finished the call with her, went outside (the call was 15 min) and bye bye car. Even with the engine on only some of the time, I guess they went by it when it was running. 8 AM in broad daylight.

    Well! I won't do that again. Monday morning brain fog.

    Learn from my mistakes, folks!
     
    #20 theGlass, Jan 5, 2022
(You must log in or sign up to post here.)
Page 1 of 2