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4HI button

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by JZumi, Oct 23, 2010.

  1. JZumi

    JZumi New Member

    Mar 31, 2009
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    99 Burb 4x4 with automatic. Yesterday I put it in 4HI and the light on the 4HI button was on intermittently. Is that normal or should the light stay on until I turn it off? Or is it indicating that it is deciding to kick into 4x4 automatically when needed? (If that is the case, then what is the 4Auto button for?) I did not try any other buttons. The burb seemed to handle the muddy and loose trail just fine.

    You might tell that I'm just starting to use my 4 wheel drive and I appreciate any insight and help. Thanks! John
  2. Z-71

    Z-71 New Member

    Nov 21, 2008
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    I'm not 100% sure but I think it means that it couldn't engage in 4 wheel drive.Jack it up and get all four wheels off the ground and see if they are all spinning.Or maybe someone else knows for sure...
  3. Naptime

    Naptime New Member

    May 12, 2010
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    Does the light stay on when it's in 2 or 4 auto?
    BTW 4 auto is an all wheel drive function. It uses a little more fuel as opposed to 2WD.

    You could use the 4 low and see if it's working. That is unmistakable.

    These have an issue with the button lights losing contact. Usually still engage, just the light stops indicating or becomes intermittent.
    If you try 4L and it's not engaging, you might try getting under and cleaning off that shaft and lubing it up with some grease.
    Some have had success with that.
  4. Springthing

    Springthing New Member

    Aug 27, 2008
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    If the light is flashing at you (like a turn signal) then, like Z-71 said, it is most likely an issue with the 4WD not engaging. In my experience it will flash for a little bit and then go back to 2WD. The same can happen to get from 4WD back to 2WD.

    If it is intermittent, like you it goes solid for a while...then flashes once or twice....maybe like a short? Then it would be the button, like Naptime said. The wiring at the plug in back of the button control box thing could be having issues.

    If it's flashing like a turn signal then you'll have to start diagnosing from there. Most likely, again mostly from what I've read here, it is a problem with the 4WD actuator.

    Good luck, and let us know what happens.

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