Not entirely--some '01 6CD changers had external changer capability. Easiest way is to hit your "CD" button while the unit is on. If it says, "NO CDDJ," that means that it has the capability to control an external changer. To be entirely sure, pull the radio and see if the CD changer port has pins (as opposed to being a plastic square empty of any pins).
If it has the controls + pins, click the link below.
One of the amazing things about Ford radios is that, unless you have an 04-05 canbus in a Gen1, you really don't know which radio you were getting, other than it being a single CD, 6CD or 6CD with external amp/sub controls.