Welcome! ECU part number P56041423AH for a 1999 Jeep Grand Cherokee 4.0L. Inspected and in good working condition. Computer may require professional programming, please double check with your auto technician or local dealer before buying. Also, please double check the part number to verify this item matches your vehicle. It is the buyers responsibility to make sure it matches. Includes a 30 day warranty with free return. Any questions feel free to ask and thanks for looking!