I stand corrected, you do only need one..........
For a customer to be able to program RKE transmitters themselves, at least one RKE transmitter must be programmed already. This procedure is to add additional transmitters. If all transmitters are lost, the DRB III® scan tool must be used to program the new transmitters.
1- Insert the key into the ignition switch, and turn the ignition switch to the RUN position without starting the vehicle (allow chimes to stop).
2 - Using the RKE transmitter programmed to the RKE module, press and continuously hold down the UNLOCK button for 4-10 seconds.
3 - Within the 4-10 second time range, continue to hold the UNLOCK button and press the PANIC button. Both buttons may then be released. Upon the PANIC button being depressed, the message for customer programming mode will be transmitted to the RKE module.
4 - A chime will be heard to verify that the customer programming mode has been entered (allow 3 seconds to hear chimes).
5 - Press and release any button on each transmitter that is to be programmed to the RKE module, including any transmitters which were previously programmed to the RKE module (with a maximum of four possible). After each transmitter is successfully programmed, a chime will be heard to verify that successful programming of the transmitter has occurred.
6 - After thirty seconds, or upon the ignition switch being turned OFF, the RKE module will exit programming mode.
Information is from DCX
