The Ranger has always been the truck of choice for Ford enthusiasts looking to purchase a compact truck. The Ranger has gone through changes over the years, but that has not seemed to affect its sales. The 2004 Ranger had many available configurations, including two- or four-wheel drive, several cab configurations, and engine options like the 2.3-liter four-cylinder or the 3.0-liter and 4.0-liter V-6 engines.Replacing the PCM is easy on this truck, and is in the same place on all models.
Park the vehicle on a flat surface and apply the parking brake. Turn the ignition key off and remove it from the vehicle. Install the memory saver per the manufacturer's instructions. This will help retain radio and module memory functions. Open the hood. Disconnect the negative battery cable by loosening the cable end bolt and removing the cable.
Locate the PCM under the hood on the passenger-side firewall. It has a large wiring harness plugged into it with a bolt in the middle of the connector. Loosen the center bolt until the connector releases from the PCM. Clean any debris or corrosion from the connector with the electrical cleaner. Remove the two PCM retaining nuts. Remove the PCM by pulling it gently from the firewall.
Install the new PCM. Tighten the mounting nuts until they are snug. Install the electrical connector by aligning it with the PCM and then torquing the connector nut to 62 inch-pound with the torque wrench. Install the negative battery cable. Torque the cable end bolt to 89 inch-pounds. Remove the memory saver.
