I have an 08 4.8l with 133k. Was on the freeway yesterday in 5th gear and out of nowhere my AWD 4X4 DTC lights came on as well as my brake light. The car seemed to be a little more unstable than usual (assuming the stability control was malfunctioning). As i let off the gas and made my way to an exit my transmission gear light came on and a transmission malfunction message came on. I pulled off the freeway and was stuck in 5th gear which made me accelerate like a snail at lights. Found a parking spot where I had to leave in an uber to a meeting so i didnt try starting it until 3 hours later.
Bottom Line
I came back thinking my x5 was done for. The battery surcharge light was on and started rough on first go. Looks like it was only battery issues that caused malfunctions. Anyone have any reputable batteries they recommend. I have an aftermarket sound system which pulls more energy from battery.