I'll run threw the immo3 logic so you can better understand. When you key on the cluster reads the rfid chip in the key. Then it sends a run or kill command to the ecu. They key needs to he paired with the cluster. If the rfid chip in the key was paired with another cluster prior the key will not pair with the new cluster. If this is the case at the very least you'll need a new rfid chip for the key if not a new key cut. The ecu immobilizer must be active to pair the cluster and the ecu. If the immo is turned off in the ecu you will not be able to pair the key , cluster or ecu. You need the skc (secret key code) that's stored in the ecu eeprom and also from the cluster. You'll need specialized software and a cable to read the eeproms. Once you have the eeprom dumps you can extract the skc(s) and use those to adapt your key cluster and ecu. Alternatively, you can pull a matching key and cluster from a car and turn off the immo. Turning off just the immo in the ecu without having a matching key and cluster will make the hazards flash for about 15 min. Best of luck