Trailer sway – a trailer swinging from side to side – can quickly escalate and become difficult to counter, risking serious accident, Ford points out.
The company's 'trailer sway control' (TSC) is part of the 'electronic stability program' system that comes standard in the Ranger. It uses information from the sensors on yaw, acceleration and steering angle. The result is greater driver confidence.
TSC in the Ranger will help the driver if snaking occurs, says Matt Bridger, stability control engineer, product development, Ford Australia.
"For the inexperienced, towing can be a daunting experience. You have to adapt your driving technique and pay attention to your speed, but even then weather or the actions of other road users can lead to trouble."
This is where TSC comes in.
But though technology provides an added layer of security, it cannot substitute for drivers displaying caution when towing. Excessive speed, poorly distributed loads and improperly inflated tyres can all influence the trailer stability.
Weather conditions such as slick roads and crosswinds are also factors.
"Once the trailer starts to sway, it can quickly escalate and – unless the appropriate actions are taken – cause a loss of control," Bridger says. "If you are driving above a certain speed, the swaying can increase.
"The ESC system monitors these parameters anyway, so it makes sense that we should use this information to look out for and react to trailer sway as well," Bridger says.
TSC continuously monitors the yaw rate of the vehicle and compares this to the steering angle. If swaying is detected without appropriate driver input, the vehicle is designed to react accordingly to correct the instability.
"If it detects a situation where it needs to intervene, TSC is designed to make brake and engine interventions based upon the sway severity and lateral movements caused."
For moderate sway, the front brakes will engage in a left-right alternating pattern to generate a yaw movement in the vehicle that counteracts the trailer sway. For more severe sway, engine torque is reduced to zero and brake pressures are applied to all four wheels in order to reduce the vehicle's speed below the trailer's critical speed.
