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down hill assist questions

Discussion in '2nd Gen. Tacomas (2005-2015)' started by malcolm31, Aug 5, 2010.

  1. Aug 5, 2010 at 9:35 AM
    #1
    malcolm31

    malcolm31 [OP] New Member

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    i have a 2009 tacoma DC v6 automatic transmission. I am assuming this is the downhill assist, but whatever it is it really seems to kick in going down steep (and even not so steep) grades. I am guessing this lurching is the truck downshifting. I found this great when I was hauling our 1100 pound camper in the rocky mtns., in fact I didn't even notice the lurching then, but it seems excessive when I am not hauling or towing anything. I also notice the truck revs when I make a turn onto a straight or level road after going down hill. Is this normal?
     
  2. Aug 5, 2010 at 9:49 AM
    #2
    DevL

    DevL Well-Known Member

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    DAC is a series of intermittent brake pulses (kind of ABS feeling) and only works in 4L. There is no mistaking it. It keeps you at 3 mph on steep down slopes.
     
  3. Aug 5, 2010 at 1:59 PM
    #3
    skistoy

    skistoy Make mine a Double!

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    do you have the downhill assist on a SR5? I dont
    i think its just the way the automatic transmission works
     
  4. Aug 5, 2010 at 2:05 PM
    #4
    skistoy

    skistoy Make mine a Double!

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    thought so , but didnt want to engage foot before doublechecking - haha

    Hey malcolm31 , welcome to the sight

    hold on to the wallet, the more you read and learn about
    the harder it gets to hold on the money.
    But you'll learn a great deal here.
    lets see some pic's of the truck
     
  5. Aug 5, 2010 at 6:25 PM
    #5
    David K

    David K Well-Known Member

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    x2 :)
     
  6. Aug 5, 2010 at 6:32 PM
    #6
    CopDoctor

    CopDoctor Well-Known Member

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    yep, it'll also hold gear when going up hills as well
     
  7. Aug 6, 2010 at 9:39 AM
    #7
    DevL

    DevL Well-Known Member

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    Have you had it work going uphill? I was on a 45 degree incline the other day and in 4L with my locker on (deactivates DAC) my truck didnt move with no throttle... I have only felt DAC a couple of times but never felt any hill start control... how do you know its working (manual says it uses brakes to hold you till you apply throttle for a maximum of 5 seconds)?
     
  8. Aug 6, 2010 at 12:41 PM
    #8
    CopDoctor

    CopDoctor Well-Known Member

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    no i mean when you're going up a hill, like a mountain pass, it will hold your gear so it's not hunting all over the place.
     
  9. Aug 6, 2010 at 12:51 PM
    #9
    Pugga

    Pugga Pasti-Dip Free 1983 - 2015... It was a good run

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    Your transmission works like that because we don't have a tow/haul button on the Tacoma's. It's basically in that mode all the time so the transmission holds you back on steep downhill grades and holds a gear going uphill. Mine does the same thing, including the higher revving once you go to a flat section after a hill.
     
  10. Aug 6, 2010 at 1:13 PM
    #10
    MountainEarth

    MountainEarth Well-Known Member

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    Hmmm. Mine doesn't engine brake at all. If I'm heading downhill with no throttle, it's basically free coast.

    As for DAC in 4L ... when you have it on, you can't mistake it. LOL it sounds like your truck is falling apart ... almost a grinding type noise.
     
  11. Aug 6, 2010 at 5:41 PM
    #11
    TacoAlaMode

    TacoAlaMode Mr. Midlife Crisis

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    I agree with Pugga that it is built into the truck for towing.

    I have felt it in my 10 DC. It really depends on the road and your style if you will encounter it or not, but I have a particular curve going down a mountain and when I apply the brake for a few seconds, the truck always downshifts. Then it holds that gear until I apply a little gas and it bumps back up a gear. I have approached it a little more aggressive a few times to see how it reacts and it can be a completely different response from the truck.
     
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