From the service manual: TRAILER SWAY CONTROLTrailer Sway Control (TSC) is safety feature made possible by ESP. TSC does not require driver input; it activates once the yaw sensor recognizes the unique vehicle motion associated with trailer sway and no steering input. It becomes clear that this motion has to be from a trailer and thus activates the brakes to eliminate the trailer sway.
Lobitz is correct in that the trailer wiring is not part of the TSC equation. The Yaw Sensor detects side-to-side motion and compares that motion to the steering wheel angle and movement. If the driver is not moving the wheel left or right but the vehicle has that left-right motion, then the ESP kicks in to counter it.
PM the last eight digits of your VIN and the mileage to me and I'll see if it came equipped with Trailer Tow Prep. I've seen the engine oil cooler listed in the equipment even on those without the TTP.
