I would love to know this too. Ideally, it would NOT honk when locking, but WOULD honk when a door is ajar and you try and lock it. Currently, mine is opposite of my preferred behavior. My guess is this is too specific a request.
Got my 2015 PMC this past spring. The inability to disable the horn-on-remote-lock really annoyed me. Looked in the owners manual; the Uconnect 5.0 section says it can be done! Called FCA many, many times. Got a case manager assigned to me. Finally, after about 4 months, she informed me that my vehicle is missing the chip that would allow it to be disabled. This chip would be present if the vehicle had been ordered with an certain type of alarm. I asked for compensation due to the discrepancy between the owners manual and the vehicle (there are a couple of other things that are missing from the Uconnect system). Got some oil changes and my spare tire kit paid for.
I use my PMC as a camper. If I am in a campground and get out at night, and want to re-lock, I disturb other campers. Took my PMC to the dealer who looked at it. My dealer said that there was no way to make the change.. even after insisting that others on this forum have been able to force the issue.. or get compensated
A simple fix would be to add a relay that has the coil connected to a circuit that turns on when the van is running. The switch contacts on the relay would then be connected in series with the + wire to the horn.
Car running = horn works like a horn should.... car turned off = horn will not sound when arming alarm (or when you hit the horn button)
Why do you refer to your PMC as "gasser"? I just bought a 2015 with 36,660 miles on it. The van is like brand new and was maintained and taken care of. However, I'm not getting the expected mpg I was hoping for. The computer says 19.1 mpg average but I calculated 17.6 mpg at the pump this morning. My driving in San Diego is at least 50% freeway at 65-70 mph. Are the early models less fuel efficient?