Strange MFD behavior.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jamie Samans, Oct 18, 2024.

  1. Jamie Samans

    Jamie Samans New Member

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    Hello. I recently got my MFD repaired by UpFix. Before I sent it in, it had the "sunburst" problem and some screen damage. That's now been fixed. However, before, it functioned normally, just was hard to see.

    Since I got it back, it's behaved strangely:
    • When the car is in Accessory mode (green Start), the things that should work do: prompt beeps when buttons are pressed, radio functions normally, map and destinations come up fine.
    • When the car is moved to Ignition On mode (amber Start) OR is started, the MFD stops working normally: no more beeps, very slow response to buttons, maps show "the external system is not connected," audio shows as off.
    The A/C will respond to the steering wheel but not to the MFD. The radio, if already running, continues running for a short time and then turns off. It cannot be turned back on by MFD or its buttons once that happens.

    I've seen a lot of info about how a low 12V battery can cause the MFD to not behave properly when the car is in Accessory mode. That's not the case here. The battery reports 12.0V from the vehicle diagnostic when in Acc mode, and the system check shows blue for all but radio (yellow).

    Turn the car to Ignition On, and the system check changes to four red.

    Anyone have any ideas why this is happening?
     

    Attached Files:

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  2. Tombukt2

    Tombukt2 Senior Member

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    Seems like there's a hell of a communication problem and it wasn't like that before it left you apparently so somebody hasn't done something correctly I mean I know these things can be hard to find but generally it's not too bad I don't know what this repair costs but usually if I look hard enough I find one of these things when I need it I don't have many cars with the GPS so there's always that and I don't use the GPS I'm thinking in a car without the GPS the two main plugs that have to plug in on the back of the MFD are on all of the MFD I do believe the additional plugs for the antenna for the GPS and other couple of things that need to be there for GPS if they're not plugged in they're just not there and all of that I would think I thought when I had the GPS MFD out of my car that came with it I plugged in a four-button GPS for a minute just to see if it would work and I believe it did
     
  3. dolj

    dolj Senior Member

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    NCON means there is no connection to those systems. The obvious thought is one or more of the connectors on the back are not seated properly.

    Other than that, I guess it is possible that something else is wrong with the MFD internally or that the repairer may have broken something while doing your repair.
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Any chance that you have an exchange unit (different part number?) that's not correct for your car?

    Posted via the PriusChat mobile app.
     
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  5. Jamie Samans

    Jamie Samans New Member

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    Well, I should clarify that the map not working isn't the extent of it. The MFD doesn't receive proper information from anything in Ignition On or when the car is running: no real-time battery vs engine usage or MPG, no radio, no A/C control from the MFD. The map system is just one more thing that doesn't work. What I'm trying to puzzle out is why it would work in Accessory and then not with the car started. If it were a power issue, it should have more power with the car running.