This is a good used, fully functional unit with a 30 day functionality gurantee. Unlike the expensive "remanufacturers" There is no core charge with this unit, nor do you have to send us your original unit, so you will have less down time. The price you pay is the "to your door" price, and you keep your original.This unit was runtested & is functional, and offers a 30 day warranty. Please be sure to double check the part number off your original unit before buying. A defective unit is one of the most common no start or random stalling problems with these trucks. They can also be the cause of erronious check engine lights, cold or hot start problems, or idle control malfunctions. If yours does not have problems, keep an extra ECU in the trunk, you might some day be glad you did... Thanks for looking!