I have a brand new 2015 Yukon denali (short wheel base) with less than a thousand miles and a "service 4WD" message that has appeared twice rendering the car extremely unsafe and un-drivable for a long distance and having to have it towed to the dealer twice. A software update was done on the car the first time, only resolved the issue for a few weeks, the issue re-occurred after 3 weeks. When turning the vehicle on the dash gives the message "service 4WD". the car has a transmission button to change from 2wd, auto, 4 high and 4 low. I do not touch this button, I just leave the car in auto and drive. I do not tow anything, this is just a family car used for commuting. When the "service 4WD' message appears, the car is barely drivable. When it is put in reverse, the car just brakes after a few feet, as if the parking brake were on, but it obvious is not engaged. When turning left or right, the car brakes mid-turn and will only complete the turn if 3/4 to full accelerator is applied to continue through the turn. The car slightly bucks through the turn and the engine sounds different and has little power going around corners and going up hills. The car cannot safely be driven in a straight line faster than 40-50 mph. I telephoned onstar and diagnostics were run during both occurrences with the same error message from onstar diagnostics: "the braking system has an issue- transfer case module not working as expected". when will GM issue a recall on this safety issue, I do not feel safe letting my wife and child in the car if it brakes by itself, loses power and cannot complete turns. I purchased this car to have a safe/large vehicle for my family: Service 4WD appears on screen it renders the car un-drivable and the transmission button becomes inoperable and selecting other transmission modes becomes not possible.

- Cliffside Park, NJ, USA

I just completed a claim for my 2015 Yukon denali, NHTSA id #: 10643049 and read that almost the same exact issues are going on with the 2015 Chevy Tahoe models, see: NHTSA id number: 10638437, 10633519 and 10631583. When will GM see there is a pattern and issue a recall for this transmission issue? in all cases these render the calls un-drivable and having to have them towed.

- Cliffside Park, NJ, USA