problem with computer.

Well I guess the 200 mile drive to Detroit & the $225.00 cost was a waste. truck was fine for about 250 miles, today, then the light came on again. code 23 & 53 on the yellow. red showed the same code 25. after unloading & driving 30 miles home, the light did not come back on, but I know it is ready anytime. I was hoping to get some revenue before taking more time off & having more work done. one guy at shop told me to carry my spare & if current e.c.m. goes totally out to put it on. I told him I don't know what it is off of, but I think it is off a 12.7. he said it would work.. it may not run like it should but it would get me home? this does not sound right.

I thought I could damage my engine, by putting on another e.c.m. without knowing anything about what it is programmed for. even though it is a ddec 3 as mine is. I also have a ddec4 both I bought online for under $200.00 so I thought they would be a good for a back up. the question now, is... if I leave the current e.c.m. like it is. is there a time limit on how long I can go before it no longer functions? I have read from one member on here & some others that say other than the annoying light it will not hurt anything. so far my truck runs perfect with this glitch, but am I on borrowed time? thanks for all who tune back in to help.