Actuators stopped functioning properly to control a/c and heat in vehicle when turned on. if a/c is turned on, it may run for awhile then turn to heating cycle on one side of the vehicle or the other. this happens whether the vehicle is in motion or not. if heat is called for in winter, i.e. to defrost windows, the heat may or may not run or if running may turn to a/c. many times in winter the heat turns to a/c and there is no heat entering the vehicle. noted there were numerous gmc vehicles with the same issue as late as 2015 when looking on the internet.
I noticed that the car was making a rattling sound. at low speeds you can hear it and sometimes when it is idling. seems to come from the exhaust next to the gas tank.
2004 gmc yukon. speedometer malfunctions. speedometer erratic. reads up to 120 miles per hour and vehicle traveling at 55 mph by gps tracking device. vehicle has approx. 85k miles.*dt
Recall. *nm