This topic contains 2 replies, has 2 voices, and was last updated by IrwinMFletch 3 weeks, 1 day ago.
February 27, 2023 at 8:53 pm #749148
According to the web site…
“Adaptive Cruise Control has limited braking capability, so if the vehicle you’re following stops too suddenly, you’ll get an alert to take action by quickly applying the brakes yourself.”
Based on my experience below, I’d hate to know what UNlimited braking capability might be.
I THINK Adaptive Cruise is the only safety feature that can actually apply the brakes, so with that assumption I’ll be using caution and maybe even turning it off from now on when driving into the sun – such as early morning or late evening.
I’m totally loving the feature but on a recent trip got the crap scared out of me when the truck braked really hard out of the blue with nothing in front of me for at least a quarter mile. It hard braked, then very shortly after that punched the accelerator to bring me back up to speed. I was on a 500 mile interstate run about 2 hours after sunrise, heading east. I’m just glad no one was behind me. Even following at a proper distance they would have hit me unless they were paying close attention to the road – which is unusual these days.
I doubt it exist but the next improvement would be checking behind the vehicle to see if applying the brakes might create another problem. If there’s no way out, then AI could get involved and compute the collision that would cause the less harm to the occupant based on the size of each vehicle 🙂
Next time I’ll remember to pull the SD card from my dashcam to preserve the incident and get more info. I’m only guessing but I think I went from 75 to 60 in about 1 second. I turned off adaptive cruise for the next hour. The remainder of the trip their and back it worked flawlessly.
Aside from that incident, it works AMAZINGLY well. I was thinking only imagery was being used but it must be radar too. That became obvious during my first auto-braking experience when I was approaching a vehicle that was moving allot slower than I was – and ME not actually being able to perceive that. In that case ceasing acceleration wasn’t going to be enough so it “gently” applied braking until I switched lanes.
Anyone else encountered this?
February 28, 2023 at 6:26 am #749166
I really wanted adaptive cruse control on my 2023 GMC Denali HD2500 but could not find one in stock that was equipped with it. However, after driving my truck pulling a 10,000 lbs trailer mostly on Interstates for about 5,000 miles, I must admit I’m glad I don’t have it. The non-adaptive GM cruse control with the thumb wheel adjustment on the steering wheel is much easier to use and regulate than earlier versions. In my experience, my brain and reaction times are more than adequate to make speed adjustments as needed even in emergency situations. I believe the distance alert that is included with the HD 2500 conventional cruse control system works similarly to the adaptive system that uses a combination of radar and cameras to monitor closing distance to a vehicle in front. Instead of applying brakes when closing distance rapidly diminishes, the non-adaptive system produces a very noticeable audible and visual warning. It works very well and I am very happy with the current version of GM’s non-adaptive speed control.
I am no stranger to adaptive control systems having owned four vehicles with it; three late model S-Class Mercedes and a Jaguar. The first S Class Mercedes S550 had issues with it from new and just as you experienced; it would jam on the brakes at high speed for absolutely no reason creating a severe safety concern. After many trips to the dealer , many test drives with the shop foreman, and eventually asking them to buy back my car, they finally found an intermitted conductor inside a wiring harness associated with the front radar transducers. With that replaced under warranty, the system was deemed to be fully operational. However, it still had trouble distinguishing a high median barrier on tight curves and nearby vehicles. It continued to slow the vehicle, sometimes severely by applying the brakes, under certain predictable situations. My next S550 with a “new and improved system” did exactly the same thing. Finally, I purchased a 2020 Mercedes S560 with an even more advanced adaptive speed control system and it does exactly the same thing. Over the years of driving these big Mercedes S-Class sedans all over the country in all types of weather, I have developed a habit of disengaging the speed control under these predictable situations. But my 2023 GM HD 2500 with the non-adaptive speed control experiences no such false alarms.
I don’t know how similar the GM speed control system is to what Mercedes uses but they certainly seem to operate comparably. The only problem I regularly experience is switching from one vehicle to another; some with adaptive speed control, some without and even some with no cruse control. Also, the Mercedes system includes steering assist wherein the cameras are tied into the speed control to monitor the vehicle position on the roadway. I believe the newest GMC version works similarly but can be driven completely “hands free” for longer periods of time than Mercedes. I cannot use these steering or lane control and positioning systems as the constant, automated steering adjustments induce motion sickness symptoms because my brain is not in control of the steering adjustments and therefore, cannot anticipate the lateral motion.
I will probably revisit this issue when it comes time to replace my 2023 GMC Denali HD 2500 with another but I continue to believe an alert and engaged human brain is far superior to any automated system.
February 28, 2023 at 6:42 pm #749316
Good to know I’m not alone then. Hmmm, I wonder if I can disable the braking part and just keep the audible and vibrating seat part? I was thinking the morning sun was causing the issue since in the 1000 mile round trip that’s the only time it occurred. I can imagine where the sun would affect image recognition but I’m not sure how it affects radar signals. Plus, I made the same 1000 mile round trip a few weeks earlier (a later departure time) and never experienced the issue.
My Denali did not come with the $3k autonomous steering but it does have lane assist. This has spoiled me. I wasn’t sure about it at first but it’s been very useful and hasn’t caused any problems for me. I just have to remind myself that I have to do ALL the driving in my other car! Though it works fine in the city and I’ve gotten used to the “nudges”, it’s REALLY nice on long drives down the interstate – keeping me off the bump-bump-bump center lane and the brrrrrrrrr shoulder.
Agree about the human brain part. I prefer to be a participant in the driving task. But I don’t mind allowing the truck to deal with that person in front of me, NOT using cruise control, and varying their speed plus or minus 1 or 2 MPH. I don’t miss the 30+ years of turning cruise on/off to deal with them. If they’re going close enough to the optimal speed, I just LOCK on to them.
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