Dynamic Rear Proportioning (DRP)
WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
The Dynamic Rear Proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the combination valves in the base brake system. The DRP control system is part of the operation software in the EBCM. The DRP uses active control with existing ABS in order to regulate the vehicle's rear brake pressure.