Ok a few days ago my ecm took a crap on my 99 sport a back road(mainboard inside cracked) anyway my buddy has a identical jeep as me so we swapped computers.they are the same part number,now my jeep only starts for 3 seconds then dies,we put the ecm back in his and it ran perfectly...do I need to have his reprogrammed?

 

Are your connections clean?

 

Yes

 

Most of the time it's possible to repair circuit boards. If you have a crack that is breaking a circuit connection on the board, you can use a strand or two of solid wire to bridge the crack. Not that hard if you have any soldering skills. Just scrape the varnish from the copper film on the board and solder the wire in place using a low temp iron or gun.

 

Water ruined most of it

 

Update: From what I've read I will need to have the new ECU flashed at a dealer can anyone confirm this, I hooked the computer to an scanner and it simply came up with a key detection issue.Is there anyway to by pass this system?

 

Eh. It's the smart key thing that's keeping it from starting. You'll probably have to visit the dealer to have that reset.

 

Gonna take it to the dealer for a ecu flash.