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Gen3 cruise control accel/decel program profile different from gen2?

Discussion in 'Gen 3 Prius Technical Discussion' started by RFLarcher, Jul 3, 2014.

  1. RFLarcher

    RFLarcher Junior Member

    Joined:
    May 24, 2008
    3
    1
    0
    Location:
    Farmington, CT
    Vehicle:
    2014 Prius
    Model:
    Three
    I recently bought a 2014 Prius and still own a 2008 model. Two characteristics about the cruise control seem to be different:

    (1) the 2008 holds speed very accurately and doesn't vary unless it encounters significant grade changes. The 2014 seems to wander +/- 1 mph even when grade changes are slight. The difference reminds me of NORMAL and SOFT RIDE modes in an autopilot's Altitude Hold mode where, for passenger comfort, altitude is allowed to vary some small amount rather than aggressively returning to the set altitude.

    (2) when changing speeds up or down in the 2008 (moving the CC lever momentarily up or down ... 1 mph for each "click"), the acceleration or deceleration is imperceptible. IOW there is a very smooth transition to the new speed. However, the 2014 exhibits a noticeable surge when increasing speed one "click" at a time, and a noticeable sudden "drag" when decreasing speed one "click". This seems to be inconsistent with the behavior in (1).

    Two questions here:
    1) has anyone else had this experience with either (1), (2), or both?
    2) is the there another program profile (firmware) that can be loaded in the ECS to modify CC behavior, by changing the accel/decel rate when changing speeds. I can live with (1). That's almost insignificant.

    Thanks in advance if anyone has any insight or thoughts about this. It's not a safety issue (I don't think) ... just annoying.

    Ray
     
  2. our1vue

    our1vue Member

    Joined:
    Mar 10, 2012
    313
    58
    0
    Location:
    NY
    Vehicle:
    2012 Prius
    Model:
    Two
    I know the Gen 3 inverter recall changed the cruise characteristics. Other people have noticed the variation in steady speed. I'll have to try
    the speed change via the cruise lever. I know when I "resume" a speed, it isn't as aggressive after the recall.
     
  3. GregP507

    GregP507 Senior Member

    Joined:
    Apr 5, 2014
    3,002
    480
    0
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I can't say for sure, but I think my 2012 has a fairly fine adjustment for speed control. Previous cruise controls I've used are usually set in increments, which makes it difficult to match speed with traffic over longer periods of time. So far with my 2012 PiP, it seems to be less of a problem.