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Combination meter blank, no instrument lights

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by koco, Oct 8, 2021.

  1. koco

    koco Member

    Joined:
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    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    The dark combination meter issue occurs a lot lately. I have seen some youtube temporary fixes in which they turn on accessory power then hold the climate button and switch the headlights on and off, and sometimes it works.

    With the door open I push the power button once without pressing the brake, and if the door open light does not come on I know the dash will not be lit if I start it. All I do is flash the high beams once or twice to get it working.

    I will be installing the new 220uf capacitor in the panel soon. It seems like the panel was engineered to work with the 100uf capacitor, but not to work with an aging 100uf capacitor.
     
  2. Pinback

    Pinback Member

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    Aboard The Prius Dark Star en route to Veil Nebula
    Vehicle:
    2009 Prius
    Model:
    Two

    G'day Koco,
    I have the same issue on my 2009. (The Darkstar)

    Thanks for the tips you mentioned for the quick temporary fix. I'll try those. This morning I found myself in the driveway at 2am with a car that would not shut off after the drive home from work. Ug.

    I have not yet taken the board out yet and want to order a cap from Mouser or Digikey. But I don't know the physical dimensions of the cap: Height and width. I noticed that Panic-sonic has a line of vibration resistant higher temp caps which look appealing for this repair (more so than the no name caps sold for this purpose on Amazon etc). But to make sure I order the right part I need to know the dimensions of the troublesome cap.

    I see this sort of issue often with older electronics. The power supply filter caps to logic circuits start to develop internal series resistance (ESR) and also the capacitance drops somewhat, so they are far less effective at filtering noise on the power bus and can even cause some regulators to oscillate. (LDO regulators are particularly prone to this, less so the older 78XX series) Sometimes this will cause intermittent resets of a logic circuit or the cold reset circuit might not work at all. If you get your old cap out in tact and have a meter than can do it, check the ESR (Equivalent Series Resistance) it would be interesting to see what it is. I'll check mine too and we can compare. That is only an N of 2 but it is a start.

    But Like I said, for now, dimensions would really help.

    Pinback
     
  3. nc08prius

    nc08prius New Member

    Joined:
    Dec 7, 2021
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    Location:
    Charlotte NC
    Vehicle:
    2008 Prius
    Model:
    N/A
    I just replaced this cap. Based on the other threads about the issue, this was the cap that seemed to be recommended and the one I used (no issues so far):

    UUD1C221MCL1GS

    If you search for this part on digikey or mouser sites you will see it.

    If you want to read the full thread from which I got this part number (which I would encourage), look for the stickied thread "combination meter repair - DIY"
     
  4. koco

    koco Member

    Joined:
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    Location:
    Las Vegas
    Vehicle:
    2005 Prius
    Model:
    Base
    I twisted the original capacitor off the board, soldered wires to the board and soldered the capacitor onto the other end and taped it down out of the way. The capacitor I ordered was slightly larger than the original, but it didn't matter.
     
    JohnPrius3005 likes this.