Originally Posted by Widget
The talk of reprograming shift points is an interesting one. Both previous posters seem to have credible backgrounds but seem to have differing views. I'm going to dig a bit more, but would love to get more confirmed info if BMW actually addresses parameters such as the transmission/braking when a harness is recognized. If so, I'm missing out on that.
The disagreement may be a bit of a technicality. The reprogramming required is to get the vehicle to recognize the trailer wiring module in the vehicle order, in the software. It isn't a new program for something like a transmission.
However, when the vehicle recognizes that module, and also that a trailer is connected, it can access previously dormant features that we don't have a full description of. We know it can change the camera, call on the TSC program in the DSC, and turn the park sensors off. My particular models didn't change the transmission shift points, but we are now on an updated X5 that has a next generation ZF transmission. I haven't heard about brake bias, but given that BMW are now utilizing disc drying programs and preactivating brakes, it is certainly possible. It would be interesting to read about those features.
You are missing out on the trailer stability control. I was not able to get it to activate when I tried, even towing a box trailer throug the Rockies on snow covered roads, but I liked that it was there. I could get traction control and stability control to activate, just not TSC. I do like the integrated trailer wiring module for avoidance of potential issues with multiplexed lighting circuits. And I share your interest in the simpler models. I avoided all of the fancier electronics (nav, cameras, lane departure warning, heads up display, phone integration, on board Internet) as they cause too many dealer visits IMO. Nice vehicle you've got there.