If you run into issues faxing and need to disable ECM on a Brother Fax machine that does not have a menu option this should work on most models.
TURN OFF
Menu *2864
(Maintenance Mode)
10
22
11 <— 9600 ECM off
menu set
Stop / exit
(Maintenance Mode)
99
TURN ON
Menu *2864
(Maintenance Mode)
10
22
00 <— 14400 ECM on
menu set
Stop / exit
(Maintenance Mode)
99