code 16

[Tigerpaw55]

hello all new member here, Ive got a 2002 expedition just had engine put in and now i have the theft light blinking like crazy.it will crank but not start and i am getting code 1 6 i replaced the key cylender and the transponder that goes around the switch and had locksmith come out and program everything it reset one time but after first crank code 16 kicks back in im at a loss as to what needs to be done to fix this issue, thanks in advance for any help

 

[Makrobinso]

2002 XLT had similar intermittent issue. After replacing keys, I saw a thread where another user suggesting replacing relay in the fuse box. It worked nicely