What feature prevents the trailer brakes from locking up during a sharp turn?

The feature that prevents the trailer brakes from locking up during a sharp turn is the trailer control valve. This component is designed to regulate the air pressure sent to the trailer's braking system in response to the position of the tractor's brake pedal. During a sharp turn, the trailer control valve helps to modulate the brake application, which allows for more controlled braking and prevents the wheels from locking up. This is especially important in maintaining stability and reducing the risk of skidding or loss of control.

In contrast, the anti-lock braking system (ABS) helps to prevent wheel lock-up during braking but does not specifically address the issue during sharp turns in the same way that a trailer control valve does. The emergency brake is typically a backup system that comes into play when the primary braking mechanism fails, while the brake adjustment mechanism ensures proper brake performance and maintenance but does not play a role in modulating braking during turns.