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Tow Haul Mode Question

Discussion in 'GM Powertrain' started by tbplus10, Sep 22, 2013.

  1. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    After research on different sites including a search of the GM Powertrain site I have a tech question I cant find an answer for and Im hoping someone else knows the answer or where I can find it.
    My question concerns 07 and up 6spd automatic transmissions (6l80) myc.

    When activating the Tow Haul Mode transmission shift points are changed, in addition to this what other changes happen?
    Does the timing advance?
  2. adampaul1964

    adampaul1964 Epic Member 5+ Years ROTM Winner 1000 Posts

    I was always under the impression that tow/haul mode changed shift points and pressure but did nothing to the engine, but I don't have any sources to confirm or deny this.
  3. RayVoy

    RayVoy Active Member 2 Years 1000 Posts

    I don't have all of the changes, but here are some:
    - the shift points change (as you noted)
    - the tranny will auto down shift when going down a steep hill and the brake is used.
    - there is a hold function when stopped going up a hill (as at a stop light), preventing truck from rolling back,
    - when lane change signal is used the normal 3 flashes will change to 6.

    I'll post more if I find any
  4. Kapelusprime

    Kapelusprime Member

    All of the above on my 2011, if the trailer is hitched or not.

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