Trailer Sway Control

Trailer sway control is a unique function of the stability control system using steering wheel angle information from the PSCM 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 an event is taking place, the ABS module modulates brake pressure to the appropriate brake calipers 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 trailer sway event message over the HS-CAN. 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 the trailer sway event has ended. The PCM returns engine timing and fuel injectors to normal operation and the IPC extinguishes the stability-traction control indicator (sliding car icon).

Trailer sway control only activates when vehicle speed is greater than 65 km/h (40.4 mph). Any malfunction disabling the RSC ® function of the stability control 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.