Ford 2003 Mustang Owner's Manual page 67

Your vehicle has a factory-set 5–digit code that
operates the keyless entry system. You can also
program your own 5–digit personal entry code.
The factory-set code is located:
on the owner's wallet card in the glove
compartment
taped to the computer module
When pressing the controls on the keyless entry
keypad, press the middle of the controls to ensure a
good activation.
Programming your own personal entry code
1. Enter the factory-set code (keypad will illuminate
when pressed).
2. Press the 1/2 control
within five seconds of
step 1.
3. Enter your personal
5 digit code. Enter
each digit within five
seconds of the previous one.
Do not set a code that includes five of the same
number or presents them in sequential order.
Thieves can easily figure out these types of codes.
Your personal code does not replace the permanent
code that the dealership gave you. You can use
either code to unlock your vehicle. If a second
personal code is entered, the module will erase the
first personal code in favor of the new code.
Controls and features
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