Remote entry part numbers

[Clipper]

04 Explorer with remote entry needs a new key fob and I know they are on ebay. The part number on the orginal ones is 15K601-BA and I tried an older one with part number 15K601-AA and it works. My question is how critical are the last two letters? I can find AB on ebay, Will they work? Thanks Clipper

[ncranchero]

Just some info I gathered when looking for F150 fobs:

Ford Truck Keyless Remote Fob Applications

2L3T-15K601-AA (2L3T15K601AA)
FCC ID : CWTWB1U331
CAN : 1788 104 575 (1788104575)
The 3 button (LOCK,UNLOCK AND HORN) keyless entry remote control will work with many different year and model Ford's, Lincoln's Mercury's and Mazda's Including:
• 1996-06 Ford Econoline Van E-150
• 2000-06 Ford Escape
• 2000-06 Ford Excursion
• 1998-05 Ford Explorer (2 Door)
• 1998-01 Ford Explorer (4 Door)
• 1998-06 F-150-, F-250, F-350
• 2005-06 Ford Freestyle
• 2004-06 Ford Freestar
• 1998-06 Ford Ranger
• 2000-05 Ford Sport Trac
• 1998-03 Ford Windstar
• 1998-02 Lincoln Navigator
• 1998-06 Mazda B2500, B3000, B4000
• 2001-06 Mazda Tribute
• 2005-06 Mercury Mariner
• 2004-06 Mercury Montero
• 1998-01 Mercury Mountaineer
I also have a 4 Button remote that works my 98 F150, 99 Mustang, 01 Sport Trac, 08 E250, my Mom’s 05 Escape an my uncles 03 F150. Therefore I suppose the above 3 button list, in it’s entirety, applies to this 4 button remote also.

The 4 button has these numbers on the back:
2S4T-15K601-AA
FCC ID: CWTWB1U331
CAN: 1788 104 575