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What is the BLU Logic ECU?

Discussion in 'Gen 3 Prius Audio and Electronics' started by arachni42, Oct 6, 2015.

  1. arachni42

    arachni42 Junior Member

    Joined:
    Jul 30, 2015
    9
    1
    0
    Location:
    Albany, New York
    Vehicle:
    2011 Prius
    Model:
    Two
    Background:
    I have a 2011 non-nav non-JBL Prius, which I got used.

    I first noticed this thing after installing an aftermarket head unit, and I could see that various connections behind the head unit plugged into it (including those going to the speaker), but I just left it be. I used a Metra wiring harness to hook up the head unit to the factory wiring. Since then, I installed aftermarket component speakers up front, an Axxess interface to get the steering wheel controls back, and recently an amplifier. I didn't, at that point in time, want to run new wire to all of the speakers, so I ran speaker wire from the amp (4 channels) to the Metra harness and hooked them up there. The amplifier was working, but when I turned it up loud -- not super loud, but definitely louder than the internal amplifier on my head unit has gone -- it went into protect mode. And, even after turning the volume back down, it continued to go into protect mode.

    I narrowed the problem down to the right front channel -- the other 3 channels worked as long as I didn't have the right front hooked up. To narrow it down even more, I hooked the wires from the Metra harness back to the head unit directly. (In other words, this is how it was wired before I installed the amplifier.) At this point, the head unit didn't put out any sound. I unhooked the right front speaker wires, and it worked again. I've also verified that the front right tweeter and front right woofer are functional. The problem isn't with the speakers.

    I figured that there must be a short somewhere. I saw nothing wrong visually anywhere, so I spent some time today with a multimeter trying to pin it down. The + and - wires going to the speakers aren't supposed to make a circuit... when the speakers are unplugged!!! Anyway, what it came down to was this black box labelled BLU Logic ECU. It was getting late so I put everything back, and that's as far as I got.

    To get to the point:
    I don't know what this is and would like to know more about it. I've found from searching online that it's used for Bluetooth phone connections, but I didn't find much more than that. I'm not really interested in using my phone in the car, and my head unit has Bluetooth capabilities for music (although I haven't used that so far, either). What else does it do? I mean, there are a lot of wires going through it... What systems does it have its hands in?

    There are four tempting screws on the bottom; I'm keen on opening it up if I can and taking a look, but I'd welcome any other information about it.
     
  2. arachni42

    arachni42 Junior Member

    Joined:
    Jul 30, 2015
    9
    1
    0
    Location:
    Albany, New York
    Vehicle:
    2011 Prius
    Model:
    Two
    So, I did indeed go back in and take a look at the BLU Logic ECU. In terms of locating a problem, opening it up was bust; I didn't see anything obviously damaged. But there are a lot of small electronics in there. On the other hand, I don't need it, so to solve my problem I can bypass it. I still haven't felt like running new wire, so I cut/stripped the factory wire going to the front right speakers and connected them to the wires going to the head unit. (Well, actually, at first I connected them to the wires from my Metra wiring harness by mistake, which is basically just connecting them to themselves, then wondered why it wasn't working. Derp. It worked once I connected them to the head unit. I'm glad I have some Posi-Locks, which has made all this wiring switching easy.)

    For the curious, I did take some pictures of the plugs and the inside of the BLU Logic. Interestingly, although all of the speaker wires coming from the head unit are plugged in, only the front speaker wires really go through this thing.
    BLULogicECUwiring1.jpg
    BLULogicECUwiring2.jpg
    BLULogicECUinside.jpg