hello all! i own a 1991 chevy kodiak c70hd with the 6.0l engine.
i am currently experiencing issues with the ecm and PROM.
my check engine light is flashing constantly (code 51?), and i have no start.

the original ecm was toast (ants got in it) and i ordered a refurbished one (after the issue above started), and it still had the same issue.
i then burned a new chip with a factory .bin file and still have the same issue.

any input would be greatly appreciated thanks!!