Dodge Ram Pickup Truck / Van 3.9 Liter Engine ECU MOPAR 4379971 Up for Sale is a Working, in excellent condition used Dodge truck 3.9 Liter engine ECU. This came out of a 1990 3.9 liter 3 speed Automatic - may fit others too. Part number listed at the top or in the large pictures. Check the part number to be sure this is right for your car, I have several of these units for Dodge van / trucks. This may fit more years than just what's listed, check your part number. If it matches, this will fit your car. This is a good used, fully functional unit with a 30 day functionality guarantee. 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. No "hidden fees" which end up costing you more money and take more of your time.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 erroneous check engine lights, cold or hot start problems, or idle control malfunctions. If yours does not have problems, at a price this good, why not keep an extra ECU in the trunk? Don't end up getting stranded and having to shell out the insane amount of money a dealer is going to want for a new one! Thanks for looking!