Mike Travis

My dealer tech that works on these says it is not possible to add this to my truck - too many expensive things to add/change and program. There are new steering wheel controls, dash indicators, error reporting modules, etc. Guess I will have to wait until the next truck. Thanks to all posters for the great comments and content! Mike

Update: 3,000 miles later and the truck is still running and shifting well. Thanks to all the posters on this topic! Mike

Thanks for the comment topgear. I was thinking that it used the radar for the following distance warning and the front crash auto breaking, which mine has both of those features. It may not be possible if they added a seperate camera or laser just for this. I will share what their answer is regardless.

I have the dealer researching this for me since I was not able to get any useful information from GM on the question. I will share what I learn here. I had a loaner with this feature for the last month, and it works really great. No need to keep shutting it off when some jumps in front of you and slows down; the system just slows to match their speed and then speeds back up to your setting when the path is clear. Really nice feature to have if you do a lot of freeway driving like me.

Thanks Topgear!

Wondering if it is possible to add adaptive cruise to my 2019 Sierra (it is loaded with all safety features front crash, cross traffic, following distance, etc.) It this just a different module I can install, or is this simply too complex to do? All input is welcome. Thanks!!

Update: The dealer found a pin pushed in on the main wiring harness connector that connects all the modules together (TCM, ECM, ABM, SLCM, ACM, etc.); while they were not able to reproduce they problem, they did drive it for 300+ miles without issue. Also with the PCM reprogramming, it really shifts well now - the hard 3-2 downshift is gone, the occasion really hard 1 -2 upshift is gone, and it really is shifting well now. Although I have only had it back for 2 days. Also, I can't complain about my dealer: they provided me a new 2020 loaded Sierra for the duration, detailed my truck and filled it full of gas too! They had it for almost 6 weeks and did as good as I could expect for such a difficult issue. I will post again in a month or so as a follow up to let all know if it is still ok.

Yes, they still have it ( a month now ), and the update today was that it set a U0155 code this morning - Steering Column Lock, so they reprogrammed the steering column lock module per #20-NA-021. So basically, they continue to try and replicate the issue again.

Yes, it is still at the dealer. They are trying to replicate the issue again so they can capture some data.

Try getting the dealer to apply this fix: #19-NA-244: Harsh 3-2 Downshift During Closed Throttle Coast Down When Coming to a Stop- (Nov 1, 2019). May help fix your problem.

New Poster; greatly enjoyed reading the posts. My issue: 2019, 10K miles, 5.3, 8-speed, 4WD. Driving down the freeway at 67 mph with cruise and suddenly, the truck jerked hard, braked hard, lit up the dash with too many messages to read, but did not drop out of cruise control. I was then running at 4K RPM to maintain 60 mph. Got off the freeway, and discovered that I had no reverse, and what appeared to be 4th gear only (rev to 3000 RPM to get rolling). Called OnStar - they could communicate with the truck but got failure codes attempting to talk all the onboard systems - TCM, BCM, Airbag, engine - 30 minutes - and could not talk to the truck. Made it home (saturday night) let it sit till Monday morning and it started and shifted just fine on the way to the dealership. The dealer said it was the engine speed sensor and they replaced it and to come get my truck. When I did, the porter driving my truck ip only got to the edge of the service drive and stopped, engine revving. Complete trans failure - no forward or reverse gears. 3 weeks later, they say updated the TCM software per #19-NA-244: Harsh 3-2 Downshift During Closed Throttle Coast Down When Coming to a Stop- (Nov 1, 2019). There is a special note on this bulletin: Note: This calibration update will NOT address any other transmission shift or performance concerns. So, they can't reproduce the issue and have no idea how to fix it. Anyone seen similar issues, or this issue? Thanks!!