Trailer Sway Control

Trailer sway control is a unique function of the vehicle dynamic system that uses steering wheel angle information from the SCCM (vehicles with active park assist) or from the PSCM (vehicles without active park assist) and the yaw information from the RCM to determine if a trailer sway event is taking place. Trailer sway is the undesirable yaw force a trailer can apply to the towing vehicle. If it is determined that an event is taking place, the ABS module modulates brake pressure to the appropriate brake caliper(s) by opening and closing the appropriate solenoid valves inside the HCU while the hydraulic pump motor is activated. At the same time, the ABS module sends a message over the HS-CAN  that a trailer sway event is taking place. When the PCM receives this message, it assists with trailer sway control by adjusting engine timing and decreasing fuel injector pulses. When the IPC receives this message, it flashes the stability/traction control indicator (sliding car icon) and displays TRAILER SWAY, REDUCE SPEED in the message center. Once the trailer sway has been corrected, the ABS module returns the solenoid valves in the HCU to their normal position, deactivates the hydraulic pump motor and sends another message over the HS-CAN  bus indicating that the event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the sliding car icon.

Trailer sway control only activates when vehicle speed is greater than 65 kmh (40.4 mph). Any malfunction that disables the RSC function of the vehicle dynamic system also disables trailer sway control. Trailer sway control can also be disabled by the driver through the menu in the message center. Regardless of the chosen state (enabled or disabled) set by the driver, trailer sway control is enabled at each ignition key cycle.