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Getting a U0073 code, control module communication bus OFF

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sbiddle, Aug 1, 2013.

  1. sbiddle

    sbiddle Junior Member

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    This is a 2008 Prius with no check engine light or other operational issues. The car runs fine. When doing a health check with a Techstream scanner (new toy), it shows the code U0073 along with U0123, 124, 126, and 293. Can anyone help to further diagnose what may be wrong?
     
    #1 sbiddle, Aug 1, 2013
  2. vincent1449p

    vincent1449p Active Member

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    Which scanner are you using?

    Your codes point to communication errors on the SIL line. Some scanners can only communicate on CAN bus but not SIL line so the problem may be your scanner and not the car itself. Does your scanner detect the Skid Control ECU, Gateway ECU and the Power Steering ECU? All these ECUs run on SIL line.

    Vincent
     
    #2 vincent1449p, Aug 1, 2013
  3. nh7o

    nh7o Off grid since 1980

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    Those DTC get stored, and will also set the warning indicator if they are currently active. If there is no indicator lit, then you should be able to clear them. Something happened in the past apparently, but was transient.
     
    #3 nh7o, Aug 2, 2013
  4. Drdiesel

    Drdiesel Active Member

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    I wouldn't worry about anything just yet. Record all the DTC's and clear the system.
    Drive the car and re-check it. If any come back, then you can start to find out what's happening.

    BTW! Where did you get your TechStream and how much was it, if you don't mind. Thanks!
     
    #4 Drdiesel, Aug 2, 2013
  5. Drdiesel

    Drdiesel Active Member

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    Here's some DTC information.
     

    Attached Files:

    #5 Drdiesel, Aug 2, 2013
  6. sbiddle

    sbiddle Junior Member

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    Thanks for the replies. I bought the china ebay Techstream CD with OBD connector for around $30. The software works great. The biggest issue was getting my Vista laptop to duel boot with Windows XP. The software requires 32 bit XP to run.
     
    #6 sbiddle, Aug 2, 2013
  7. Drdiesel

    Drdiesel Active Member

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    Do you have a link ? Thanks!
     
    #7 Drdiesel, Aug 3, 2013
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    1. One possibility is that your scanner is generating bogus DTC since you don't see any of the skid control ECU warning lights on [such as ABS, VSC, or ((!))].

    2. If the codes are valid, then the skid control ECU has lost communication with various sensors as well as the HV ECU.

    3. I agree with the suggestion that you should clear the DTC and see what happens. If you don't see any warning lights appear then I would not worry about this.
     
    #8 Patrick Wong, Aug 3, 2013
    dave77 likes this.
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