Jerry455

I would be surprised if AC Delco ULV is not a Mobil fluid.

I bought a used 2021 Suburban 6.2 HC in May of 2024 with 70,000 miles. I had to put in a new trans at 80,000. I don't know the maintenance done but after using the Dexron ULV, I am going to be replacing fluid at least every other year. You have to shake it before using it. It is like pink water. I am not very confident in its long term use. I think the additives wear out. I am going to be installing a larger pan with a drain plug. Next Gen transmission has some interesting articles.

I ride on the rode, very defensively, and off road. I do triathlons and sometimes ride on the roads to train. I am very careful and try to be courteous to drivers. Some members of our club are not. Colorado was the worst I have ever seen. They were riding in a pack of about 30 and didn't care if they held up traffic. Some areas I will ride on the sidewalk but I slow down around pedestrians and give plenty of warning when passing. Here in Michigan, lately everyone has very dark tinting on the side windows and even the windshield. If I can't see the driver, I won't cross in front of them. Sometimes they wave me on, I can't see them through their tinting, and then roll down the window to say to cross. I explain that their tinting is so dark I can't see them. They didn't realize that.

There is also a bulletin 26-NA-038, Glass Breakage Loop, that could also be an issue. The dealer should be diagnosing this not you. Take it in and let them fix it. Cadillac has a very good warranty and dealer services, make them take care of you.

Check the coolant level in the overflow bottle. It is on the passenger side. If it is low, there might be air in the cooling system, heater core, and making sound.

I have a 2021 also. It will automatically come on when parked on an incline. My driveway is not very steep but it comes on everytime I park at home. You have to push the park brake button to turn it off. It does not take much of an incline for it to activate.

GM has released the accessory kit to do this, 87826828 for Chevrolet and 87826829 for GMC.