Trouble codes after skid control ECU replacement

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Earthiest, Dec 6, 2018.

  1. Earthiest

    Earthiest Junior Member

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    Hi All,

    I'm having trouble clearing several codes after replacing the skid control ECU. The good news was that I could replace the ECU without removing the dash or paying the dealer ship $3000, the bad news is I now have codes U0123, U0124, U0126, B1421, B1423.

    The "B - Air conditioning" codes were probably always there and I don't think are correlated.

    The "U" codes are communications codes suggesting poor wire contacts. I un-plugged and re-plugged in the wiring to the skid control (abs) ECU, reset codes, then rechecked and the "U" codes are still on. The battery charge is at 12.35 at the posts and 11.75 with the high beams on. A bit of a drop on the 5 YO optima battery, If I hadn't just replaced the ECU I would be more inclined to blame the 12V battery. As it is I don't know what else to check though. Of course the ABS and brake recovery is not working with the fault codes so mileage is down 5 points.

    Any suggestions on where I should go from here are appreciated.

    Thanks

    Car is a 2005 Gen2 with 291,000
     
  2. SFO

    SFO Senior Member

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    Would start with the 12v and charging it up, if possible.

    What kind of hybrid compatible OBD2 reader are you using?

    Did you calibrate after replacing?

    Might be time to bring @strawbrad in for help with this.
     
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  3. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    It's been awhile since I had to replace a skid control ECU. Techstream is a must to recalibrate the new ECU.
     
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  4. SFO

    SFO Senior Member

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  5. Earthiest

    Earthiest Junior Member

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    Two
    Thank you for the replies, I have been out of town.

    I bought a pirated tech stream reader on amazon and a cheap dell laptop to run it. I did calibrate the skid control ECU and also did the yaw rate zero point calibration as the manual recommended. Or at least I think I did. Because the tech stream I was using did not present the same as the manual's description of using a handheld unit.

    I did what seemed to make the most sense but this is another question I had, how different is the procedure using the pirated software?
     
  6. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    Toyota's description of the procedure is very convoluted. The U codes you have match what I have seen from a bad skid Control ECU. You could try another ECU.
     
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