The answer to your question is as follows, per the Ford Workshop Manual for the vehicle referenced in your question:
Keyless Entry Keypad Code Programming
Programming a Personal Code and Keypad Association to Memory Seats and Mirrors (If Equipped)
NOTE: If the wrong code has been entered 7 times (35 consecutive button presses), the keypad will go into an anti-scan mode. This mode disables the keypad for one minute (only the lock control will operate on the keypad) and the keypad lamp will flash. The anti-scan feature will turn off after one minute of keypad inactivity, or after pressing the UNLOCK control on the Integrated Keyhead Transmitter (IKT), or after the ignition key has been turned to the ON position.
NOTE: The factory set code cannot be associated with a memory setting.
Enter the permanent factory keyless entry keypad code.
Within 5 seconds, press the 1/2 button on the keypad.
Enter the new 5-digit keyless entry keypad code. Each number must be entered within five seconds of each other.
To associate the entry code with a memory setting, enter a sixth digit to indicate which driver should be set in a memory recalled by the personal entry code:
Pressing the 1/2 button recalls driver 1 settings
Pressing the 3/4 button recalls driver 2 settings
Pressing other keypad buttons or not pressing a keypad button as a sixth digit does not set a driver and will not recall a memory setting
The doors will lock then unlock to confirm the new code is programmed.
Erasing the Personal Codes
NOTE: If the wrong code has been entered 7 times (35 consecutive button presses), the keypad will go into an anti-scan mode. This mode disables the keypad for one minute (only the lock control will operate on the keypad) and the keypad lamp will flash. The anti-scan feature will turn off after one minute of keypad inactivity, or after pressing the UNLOCK control on the IKT, or after the ignition key has been turned to the ON position.
Enter the permanent factory keyless entry keypad code.
Within 5 seconds, press the 1/2 button on the keypad and release.
Within 5 seconds, press and hold the 1/2 button on the keypad for 2 seconds.
All personal codes are now erased and only the permanent factory keyless entry keypad code will work.
You can also find this information on page 140 in the owner's guide below:
http://www.motorcraftservice.com/pubs/content/~WO8EDG/~MUS~LEN/40/08edgog1e.pdf
HOPE THIS HELPS
