Cruise control sometimes over-revs engine on 2005 Outback

Discussion in 'Subaru Outback' started by Guest, Sep 29, 2004.

  1. Guest

    Guest Guest

    Just finished a 5000 km trip in a 2005 auto OBW with a lot of time on
    freeways at 75 mph.

    When using cruise control at high speeds (75-80 mph) and a moderate
    hill is encountered forcing the auto to change down to 3rd, it often
    then changes right down to 2nd immediately, with the result that the
    engine screams right up to redline. Very disconcerting, not to
    mention potentially damaging! I had to immediately get back into 3rd
    by flicking to manual and changing up.

    This only happens when in cruise control, not when in normal outo
    mode.

    Is this a fault or normal behaviour?

    Apart from this one glitch I found the car an absolute dream for
    touring, handling everything from freeways to high altitude dirt roads
    safely and comfortably.
     
    Guest, Sep 29, 2004
    #1
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  2. Guest

    CompUser Guest

    It's an 05, take it back to dealership and get a
    write-up, ASAP.
     
    CompUser, Sep 29, 2004
    #2
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  3. Guest

    Edward Hayes Guest

    It doesn't sound as if it's working correctly. My 2000 does not do this. I
    think if you run into dealer resistance you may suggest politely that it's a
    safety issue for people and not just the engine. What if this happened on
    wet or a sandy patch in the road??ed
     
    Edward Hayes, Sep 29, 2004
    #3
  4. My 2002 LLBean H-6 does this under the same
    circumstances, only it doesn't shift down past 3rd.

    Since it wasn't a big issue, I never had it looked at
    since other cars I've owned tended to downshift the
    trans more during cruise control.
     
    Skweezieweezie, Sep 29, 2004
    #4
  5. Guest

    Ron Joiner Guest

    I have the same car. I don't encounter the problem tp the point that you
    encounter but the 05 is a lot better going up hills than an 00 I had
    previously. I also find the cruise somewhat sensitive to speed changes.
    If your driving habits are such that you are fairly aggressive even at
    low speeds the computer will, in a sense, learn your driving style and
    adjust the shift points accordingly.

    When going up moderate hills I either go into manual and stay in 3rd, or
    switch off cruise entirely when going up steeper grades.

    All that aside, it is a Subie engine and boxer engines are quite content
    at high revs.

    Ron
     
    Ron Joiner, Sep 29, 2004
    #5
  6. Guest

    FNO Guest

    You shouldn't be using cruise control on wet or slippery roads so the safety
    issue won't help you. The cruise control on Subarus is very agressive.
    However, if it is doing that on cruise, it usually means the car is down on
    power for some reason. I would take it back and have them look at it and
    why the car might not be at full power.
     
    FNO, Sep 30, 2004
    #6
  7. Guest

    Guest Guest

    I wouldn't set CC on anthing else but freeways and similar roads in
    good condition.
    The car has plenty of power - better than I had ever expected for an
    unblown 2.5L - so that's not the problem. It only happens at high
    speed on hills just steep enough to make it change down to 3rd.

    I think the problem must be either in the software or settings but
    will be taking it to dealer next week anyway to see if they have any
    answers.

    Incidentally, I've seen several mentions here that the auto tranny
    computer "learns" from the dirver's style but I haven't read anything
    about that in the manual or in Subaru ads, so where does that info (or
    Subaruan myth?) come from?
     
    Guest, Oct 1, 2004
    #7
  8. Guest

    FNO Guest

    What I am implying is that you may have a little less power (paticularly,
    torque) than you should, and the aggressive cruise control is causing the
    transmission to drop two gears instead of one. If you are not on cruise
    control, you would tend to be a little less aggressive with the gas pedal.
    Generally, you don't see the cruise redlining the car; they aren't supposed
    to be that aggressive.

    As for the learning, I am not sure what they mean with the automatic. All
    of them have adaptive ECUs and the ECU learns from the driver to optimize
    ignition timing etc.; and that happens on both manual and automatic. I'm
    not sure how the transmission would 'learn' anything; nor why it needs to.
     
    FNO, Oct 1, 2004
    #8

  9. IMO, one area that Subaru has never gotten a good handle on is the auto-trans programming. In any
    given year there seems to be glitches of one sort or another (i.e. shift-points, temperature-related
    anomalies, and occasional bizzarre behaviour, etc.). -Danny
     
    Danny Russell, Oct 1, 2004
    #9
  10. Guest

    Edward Hayes Guest

    The TCM does learn from your driving style. It is reflected in the shift
    points and speed of shifts. It is not immediately noticeable as it averages
    so it takes several tanks of gas to make noticeable changes. I you wish to
    reset the TMC & ECM to the default settings just disconnect the negative
    battery terminal for 30 minutes or so and press the brake peddle several
    times to assure all residual volter is bled off. Ed
     
    Edward Hayes, Oct 1, 2004
    #10
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