2009 Sonata & Cruise Control Auto Trans Problem

Discussion in 'Hyundai Sonata' started by Sjtcar, Sep 11, 2009.

  1. Sjtcar

    Sjtcar Guest

    2009 Sonata w/i4 Engine & Automatic Transmission problem when using

    Problem: The car will not stay in 5th gear with the torque converter
    locked up when encountering the slightest incline while the cruise
    control is activated. Instead, the car will 5-4 shift, unlock the
    converter, go awhile, do a 4-5 shift, then do a 5-4 shift, so on and
    so forth. This is an undesired operation of the engine/transmission
    ONLY while the cruise control is activated. This has happen on eight
    of the 2009 Sonata's I have experimented with.

    If the cruise control is OFF and you are just using the gas pedal, the
    trans will stay in 5th gear, and the torque converter will stay
    locked, on even bigger hills, and you can even accellerate gently
    without the transmission doing a downshift. This is the desired
    operation of the engine/trans that should also happen when the cruise
    control is enabled.

    I have asked the dealer to fix this problem so the the cruise control
    operation of the transmission/engine will more closely pattern itself
    to non-cruise control operation. They say that they cannot because
    Hyundai USA has not released a software upgrade to fix the problem
    even though the vehicle is a one model year old and the 2010's are
    programed the same.

    If this is happening to you, find it irritating and fuel inefficient,
    and you would like it fixed, I encourage you to inform your dealer and
    to call Hyundai USA customer service at 800-633-5151 and make your
    wishes known. (Their phone number & address are at http://www.hyundaiusa.com
    located under the "about Hyundai Tab" - "Contact us"). I have already
    made their engineering dept well aware of this problem.
    Sjtcar, Sep 11, 2009
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  2. Sjtcar

    ---MIKE--- Guest

    My 2008 Elantra does the same thing. I assume that it is the cruise
    control's effort to maintain the set speed.

    ---MIKE---, Sep 11, 2009
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  3. Sjtcar

    Larry W Guest

    My 2009 V6 did "busy shifting" with/without cruise on slight hills. Car
    was an early production model. Had dealer do a TCM Calibration Update
    (TSB 09-AT-005) and that improved the situation. Have dealer check to
    see if you need to have that update.

    Larry W, Sep 12, 2009
  4. Sjtcar

    Larry W Guest

    Just checked the TSB. It was for the V6 only. Sorry for the

    Larry W, Sep 12, 2009
  5. Sjtcar

    Kent Jones Guest

    On Fri, 11 Sep 2009 11:42:08 -0700 (PDT), Sjtcar

    I found the solution was to move the auto shifter to the right when
    you were at the correct speed and gear. This way the trans will not
    shift up/down until the shifter is returned to the left (or you
    manually shift down/up by using the shift-o-matic (don't have my
    manual in front of me so I think it is called this).
    Kent Jones, Sep 12, 2009
  6. Sjtcar

    Kent Jones Guest

    On Fri, 11 Sep 2009 11:42:08 -0700 (PDT), Sjtcar

    I found this irritating also. It was suggested (and it works rather
    well) to move the auto stick to the right. When in this position the
    trans will not shift up or down until the shifter is moved back to the
    Kent Jones, Sep 12, 2009
  7. Sjtcar

    SB Guest

    "move the auto stick to the right"

    Do you mean shift into a lower gear?
    SB, Sep 12, 2009
  8. Sjtcar

    Ed Pawlowski Guest

    I don't know about the 4, but on the 6 the transmission goes into manual
    mode by pushing the stick to the right. It will only up or down shift if
    the speed is far out of tolerance, like first gear at 5000 RPM
    Ed Pawlowski, Sep 12, 2009
  9. Sjtcar

    SB Guest

    Oh yeah that's right, I recall that now. Well the Mrs drives the thing
    99.9% of the time - it's hers. I'm happy driving my GMC Sierra.
    SB, Sep 12, 2009
  10. Sjtcar

    Sjtcar Guest

    This is not so much a solution as an intermediate workaround. The
    torque converter will still unlock using the "Sportmatic" method of
    locking into 5th gear. Also, by defination, the cruise control is not
    working correctly according to page 94 of the owners manual. This is
    why I would like Hyundai to issue a software upgrade that would make
    the cruise control operation mirror the non- cruise control operation
    of the engine/transmission shifting pattern.
    Sjtcar, Sep 13, 2009
  11. Sjtcar

    Kent Jones Guest

    No. Moving the stick to the right puts the auto trans into the manual
    gate mode (see page 9 of the manual - Sports Mode) where you can
    manually shift up or down (with some limits).
    Kent Jones, Sep 13, 2009
  12. Sjtcar

    hyundaitech Guest

    Indeed, the way you describe the issue makes it seem like the cruise
    control is operating as programmed. Without any programming changes
    being released by Hyundai, there's little any dealer can do to change
    this. In that sense, you're on the right track to achieving a
    resolution to the issue. Whether Hyundai issues a change depends on
    whether the engineers believe that making the change will adversely
    affect the cruise operation and whether Hyundai believes the benefits
    of the change outweigh the consequences.

    I don't recall any cruise complaints on this model, so I haven't been
    experimenting with it's operation. At what speed(s) does this issue

    On the other hand, I just read the cruise control portion of section
    one owner's manual and fail to see what part of the description is in
    disagreement with the manner of operation you describe. Can you point
    me more specifically to which portion of the description you feel the
    operation fails to satisfy?
    hyundaitech, Sep 14, 2009
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