Ecu swap and truck won't run....no security light??

[bprince45]

Ok guys. I'm sure there are plenty of threads like this but probably not my particular situation. Bought a 98 k1500 with a pretty bad body (tons of Bondo). Found a 98 c1500 with a great donor body. Swapped body from c1500 over to k1500 frame. With the k1500 ecu truck starts but dies. I know it sounds like passlock but the security light doesn't illuminate on either gauge cluster. I read about a chip in a grey box under the dash. Swapped those and still nothing. Tried the relearn twice....still nothing. With the c 1500 ecu truck runs rough (multiple misfire code). What gets me is with the c, the gas gauge doesn't work. With the k it does. Are these ecus pinned differently? Any help would be appreciated.

 

[jigsaw]

U need to do the 30 minute relearn if it takes u less than that you are doing it wrong. Keep the k1500 ecu as its configured different to a 2wd and do the 30 min procedure sounds like its vats if its running only a couple of seconds and stalling