System and Method for Failsafe Operation of a Tractor Protection Control Module

An electronically-controlled tractor protection control module in a tractor prevents air flow from an air reservoir to a gladhand when a signal is received that indicates a trailer is not coupled with the gladhand. This prevents air from being vented out the gladhand when the tractor's service brakes are applied. However, a failure can occur that prevents this signal from being received or acted upon, which would result in air being vented out the gladhand. To address this problem, an air flow restrictor is used to limit the amount of air that is vented in such a situation.