Your Jeep's powertrain control module, or PCM, is basically the equivalent to a computer's central processing unit. It is used to relay information from all of your Jeeps electrical relays. It also relays engine trouble and problems to the driver and helps to automatically regulate some functions like air-fuel mixtures and piston firing. Wiring your PCM is a fairly simple matter that only involves connecting two wires. It can be done in about 15 minutes.
Slide your Jeep's new PCM into the area where your old PCM was mounted before you removed it.
Use your socket set to replace the mounting bolts at the bottom of your PCM to hold it in place.
Connect the positive connection wire which branches off from your battery's positive cable to the positive connection terminal on your Jeep's new PCM. It will be clearly marked positive (+).
Connect the ground wire to the negative connection terminal on your Jeep's new PCM.
Replace both the negative and positive battery cables on your Jeep with your socket set.
