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

Techstream won't connect to ECU when it had before. Thoughts?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Paul Crutcher, May 25, 2022.

  1. Paul Crutcher

    Paul Crutcher New Member

    Joined:
    May 25, 2022
    3
    0
    0
    Location:
    Texas, USA
    Vehicle:
    2009 Prius
    Model:
    LE
    So I have a 09 base w/o smart key. I replaced the abs actuator 2x. 1st time the unit sold to me from a junkyard was bad but able to communicate via ECU with techstream. Second time, it works, but I can't connect to the ECU now via techstream.

    It had been a month between the two events and I haven't done anything with my laptop like updates or anything software wise to change it. Could it be a now bad USB mini vci cable even though it worked before?

    Any other ideas? Maybe a fuse or pushed in pin for the OBDii connector? My eyes are bad so I can't visually see from the floorboard if that's the case.
     
    #1 Paul Crutcher, May 25, 2022
  2. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,676
    1,718
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    Does your Techstream connect to the car at all? Can it talk to any other ecu's? Bad terminal fit is possible, but can be difficult to verify as you need a single male terminal of correct size to check fit. And there is almost no slack in the harness to get the OBD connector out in the open.

    The brake actuator assembly in the engine compartment is a bunch of solenoids, sensors, and plumbing. It's "dumb" inputs and outputs going to the brake or skid control ecu (located in the passenger compartment).

    Replacing the actuator shouldn't affect ecu communication - as long as nothing in the actuator is shorted and is "pulling down" a voltage reference circuit. Something like that usually prevents the ecu from functioning at all.

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, May 26, 2022
  3. Paul Crutcher

    Paul Crutcher New Member

    Joined:
    May 25, 2022
    3
    0
    0
    Location:
    Texas, USA
    Vehicle:
    2009 Prius
    Model:
    LE
    I found out it was the cable. However, I have new issues so I had started a new thread.
     
    #3 Paul Crutcher, May 30, 2022
(You must log in or sign up to post here.)