(Vehicles with automatic transmissions) Banks' electronic braking device automatically activates when conditions call for braking. SmartLock locks the torque converter and simultaneously raises transmission-line pressure, to smoothly reduce vehicle speed. Besides saving wear-and-tear on your service brakes, SmartLock prolongs automatic transmission durability by increasing its holding capacity, eliminating excessive clutch slippage, and cooling transmission-fluid temperatures. For use with Banks Brake. Includes: Integrated electronic SmartLock module, Wire loom, Mounting hardware. This product fits all 2003 models, but for 2004 it is only designed to work with vehicle's that have the PCM located on the passenger side firewall behind the battery. Your Banks representative will be more than happy to help you determine which products are engineered for your specific vehicle.