I have a 2019 XJ R-Sport with adaptive cruise. Absolutely love it and living in Chicago actually use it way more for low speed bumper to bumper traffic than high speed runs. It's been a lifesaver for my sanity on my absolutely horrible commute to the suburbs for work. The one gripe I have with it is that you can only activate it at or above 20mph. I have to turn it on before I get into bumper to bumper traffic, which is generally fine. The issue comes in when someone cuts me off or merges suddenly and I have to brake thereby disabling the cruise. I then have no chance to get up to 20mph in rush hour traffic to activate it again.

Does anyone have an idea if/how it would be possible to lower the minimum activation threshold for the adaptive cruise from 20mph down to say 5 or 10mph? I assume this would all be in the ECU or the BCM somewhere but figured I'd ask as I know we have many technical experts in this community that may have an answer.

Sidenote, having had a few cars now including Volvos, Hyundai/Kia, and a few Americans, the Jag is by far my favorite daily especially in really bad traffic. The cockpit is a great place to be! 3 months of ownership and it's the happiest I've been with a vehicle!

 

If you are comfortable with getting SDD up and running, I believe there is a CCF variable that can be changed to enable low speed ACC.

 

Figured out a way around it that actually works well with no mods needed. If you have to cancel cruise like I do if someone cuts in front, it seems that as long as you hit the "Res" or Resume Cruise button within a minute or two it'll pick up right back where you left off. Learned this clicking around in traffic. This may seem obvious to some but didn't occur to me that it could be a valid solution. Thank you all for your thoughts and assistance!