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Tell me all about the Combination Meter

Discussion in 'Gen 2 Prius Technical Discussion' started by wlai, May 14, 2018.

  1. wlai

    wlai Junior Member

    Joined:
    Sep 22, 2007
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    Location:
    Pacific NW USA
    Vehicle:
    2008 Prius
    Model:
    Touring
    So I've been getting the Red Triangle warning light and some ABS/VSC/TRAC warning lights on the panel a few weeks earlier (see this post). I reset all the DTC via mVCI and drove it some more, and found that I only have this code during the last few weeks B1271.

    However, there are a number of coincidental things that I am thinking is all related:
    - My dash light brightness toggles on and off between max brightness to min brightness randomly. If I fidget with the dash brightness dial next to driver door it will reset itself for a while before going flaky again.
    - Whenever I am braking hard on a steep downhill, or cornering hard, (higher G force) the Red Warning light comes on for a few seconds and then when I'm stopped or back to normal it goes away. The BT1271 is all that is stored.
    - There has been a few times in years past where the START button won't work but it went away and hasn't happened much in the last year or so.

    Could these be all related to the Combination Meter? Particularly the brightness thing, as I thought it may have been just a dirty electrical connection of the dial.

    What does the Combination Meter does anyway, besides the display aspect of it? It seems like it has a more important function than just "outputting" the information to a display, e.g. car wont' start without it.

    Also, I heard about the recall / extended warranty issue. I have a 2008 at 170K mi. Would that still be covered?

    Thanks!
     
  2. ChapmanF

    ChapmanF Senior Member

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    Vehicle:
    2010 Prius
    Model:
    IV
    Hi ,

    If you sign in at techinfo.toyota.com ($15 for two days), one thing you will find there is called the New Car Features manual, which is the very best place to turn when you want to learn all about "what does X thing do anyway?" about your car. In one section it lays out the structure of the car's networks and the role the CM plays in them.

    It sounds like you may have multiple things going on. One (mundane, but scary) possibility for the red light momentarily appearing under higher G forces is that you might have an oil level low enough that the G forces slosh it away from the oil pump pickup, the pump sucks air, and the red light is an oil pressure warning. Mundane, because a lot of people still seem to use that as their "time to add some oil" signal, but scary because every time it happens some of the engine goes away.

    -Chap
     
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  3. jerrymildred

    jerrymildred Senior Member

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    Vehicle:
    2017 Prius
    Model:
    Two
    Excellent turn of phrase, Chap!

    Yes, check the oil first. As in before you start the car again.

    Also, I'd check the charge on the 12V battery just to be safe. That's probably not it, but it only takes a few seconds to know for sure. If that checks out, then check with Matt @Texas Hybrid Batteries. He's one of the people who can help with the CM. (Texas Prius Battery Replacement)
     
  4. SFO

    SFO Senior Member

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  5. imwoody36

    imwoody36 the prius parts guy

    Joined:
    Sep 29, 2005
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    Location:
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    Vehicle:
    2008 Prius
    the big clue here is " when I am cornering hard" I have seen this for two reasons
    1. you are very low on engine oil
    2. the driver door dome light switch is opening when you lean on the door ( because the seatbelt was closed in the door and the inside of the door is bent) this is usually fixed by adding a spacer to the door where the dome light switch rests ( say some layers of tape or what have you)
     
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