Locating the Calibration Code for the Ford Powerstroke

1994-97 Pickup
Locate the power brake booster under the hood of the vehicle. Between the brake booster and the left fender will be two plug in receptacles mounted to the firewall. The receptacle closest to the firewall is the ECU. On the fender side of the ECU right up next to the firewall will be a black and white sticker indicating the code. This sticker is not visible unless a mirror is used between the ECU and the fender. When using the mirror remember that the image is reversed. You are looking for 3 letters followed by a number (NAW4).

1999-2003 Pickup
Accessing the code on these vehicles can be much simpler. Open the driver's door of the vehicle while sitting in the drivers seat. Look down by your left knee on the hinge side of the door. There should be a white sticker with black print indicating the 4 digit code - three letters followed by a number (XLE4).
If this sticker is not readable or is missing the next easiest place to access this code is underneath the hood. In order to read the code you will need an extension mirror and a flashlight. The ECU is located on the firewall close to the left front fender underneath the power distribution box. The code is located on the fender side of the ECU next to the firewall. Remember when using a mirror the mirror the letters and number will be reversed.

If neither of these ways provide positive results then the ECU can be removed and the plastic cover slid back. The code will be on the back side of ECU is removed by first disconnecting the battery ground cables and then loosening the bolt holding the electrical connector to the ECU in the engine compartment side. Then underneath the dash locate the ECU next to the emergency brake pedal. Loosen the two 7mm hex bolts on the rear position of the black plastic box. Remove the box and ECU out of the plastic box. The code will be printed on the plastic cap on the back of the ECU.