rayford Posted February 4, 2013 Share Posted February 4, 2013 I have a 2008 LS460. When I use the cruise control arm to increase the speed of the car, the car downshifts and accelerates extremely hard no matter the speed or road conditions (uphill, downhill, level) Has anyone else experienced this? Can this be adjusted to be more smooth? I've previously owned an 92 LS400, a 98 GS400, and an 04 LS430. None of these cars had this occur and each of these other vehicles exhibited very smooth cruise control speed adjustments. Quote Link to comment Share on other sites More sharing options...
Jeff in TX Posted February 4, 2013 Share Posted February 4, 2013 Are you referring to a regular old Cruise Control? Or a Dynamic Radar Cruise Control? Or a Dynamic Laser Cruise Control? Or something else? Quote Link to comment Share on other sites More sharing options...
rayford Posted February 4, 2013 Author Share Posted February 4, 2013 Are you referring to a regular old Cruise Control? Or a Dynamic Radar Cruise Control? Or a Dynamic Laser Cruise Control? Or something else? Quote Link to comment Share on other sites More sharing options...
NoNoise Posted February 5, 2013 Share Posted February 5, 2013 I have a 2012 LS460 AWD that does exactly the same thing. My 2004 ES330 accelerates smoothly with rarely a downshift when I use the cruise control lever. In order to avoid the problem with the 460, I accelerate with the accelerator pedal and then set the lever to hold the speed. Once the speed is set and the car climbs a hill it will downshift very smoothly. If I am cruising at 72 mph and slowdown to say 30 mph and then hit the lever, the car does not downshift and gets back to 72 very sedately. If someone knows of a simple adjustment, I'm all ears. Quote Link to comment Share on other sites More sharing options...
Jeff in TX Posted February 15, 2013 Share Posted February 15, 2013 Injudicious operation of the cruise control might produce the conditions you are concerned about but cruise controls have always functioned that way so, since your car seems different from your experience with your previous cars, perhaps something is wrong with your car. Most owner manuals are not very clear about how to operate the cruise control. Just in case you don’t have a good understanding about the subtleties of the cruise control operation this might be a good time to review how it works. The cruise control is operated from a stem on the side of the steering column. The stem has a button on the end that toggles between cruise control on and cruise control off. An indicator in the instrument cluster is illuminated “Cruise” when the cruise control is on and extinguished when the cruise control is off. Pressing down, toward the floor, on the cruise control stem has two functions. If the cruise control is On and a “set point” has not been entered into the cruise control memory, pressing down on the stem will enter the current speed, as long as it is greater than 25 MPH, into the memory as the “set point.” If the set point has already been entered, and the cruise control in engaged, then pressing down on the stem will lower the set point. Raising up on the stem will have no effect if there is no set point in the cruise control memory. If there is a set point in the memory and the cruise control is engaged and you raise the stem the cruise control will raise the set point in memory. If there is a set point in the memory and the cruise control is disengaged then when you raise the stem the cruise control will “resume” using the set point from memory. If the set point is significantly above the current speed when you resume you can expect some pretty aggressive acceleration and, in the case of 5 speed transmissions that have coasted down, some significant down shifting. The cruise control is “disengaged” when the stem is pulled toward the driver or the brake is depressed. The set point is deleted from memory when the cruise control is turned off by depressing the button on the end of the stem or when the speed drops below 25 MPH. Many cars disable the cruise control when the windshield wipers are engaged and I expect the LS460 does that too. An example of unwise operation would be when you are using your cruise control to maintain your speed at 75 MPH and you touch the brake to slowdown, disengaging the speed control, and allow the car to coast down to 30 MPH and then lifting up on the control stem. Remember now, the set point is at 75 MPH, and the cruise control is only disengaged and when you lift the stem it will be a “resume” command. That is like stepping on the accelerator pretty hard to take your car from 30 MPH to 75 MPH. The smart transmissions are designed to coast down, I think in neutral, as a fuel conservation feature so it will certainly down shift when it gets the demand to increase speed. The wise way to manage this condition, if you want to use the resume, is to use the accelerator to restore the current speed to near the set point speed before you lift the stem to resume. In other words, use the accelerator to get the speed in the 70-80 MPH range before you give it the resume command. When you do that the speed will settle on the set point. If you want to start over, without dropping below 25 MPH, then just turn the cruise control off and then back on using the button on the end of the stem. The DLCCs and DRCCs have some additional subtitles that you have to consider. Quote Link to comment Share on other sites More sharing options...
craigamuir Posted July 16, 2014 Share Posted July 16, 2014 I originally had an LS400 with a silky smooth cruise control when you pushed the lever up. It gained speed very slowly until you released the lever. When I first drove my 2010 LS, the cruise up lever was so bad I took it to the dealer, who advised me that it was performing "as designed". If you hold the lever up for more than .5 sec but less than 1.5 secs, the 2010 cruise is designed to respond by raising your speed by exactly 1.5 mph. The 2010 control was changed from continuous (2000) to discrete. If you hold the 2010's lever in the up position for 2 secs or more, the control will gun the accelerator. Quote Link to comment Share on other sites More sharing options...
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