c5 pcm woes

[dgumoe]

hey guys, im about to ask a BIG favor. so go easy on me please. ive got a 99 corvette. we just finished the engine transplant it so sorely needed but now ive suffered a pcm failure. (i think) the 10 amp fuse that supplies battery power to the pcm is blowing instantly. and thus i have no fuel pumps, no power to the solonoid wire on start, and my fuel gage is pegged at zero (the tanks are full) here's what i do know about this circuit. it is always hot. so key on key off makes no matter. yes its supposed to be hot. im quite sure that the pcm is shot and that is whats causing the short (the fuse wont blow if the pcm isnt hooked up). common sense would say replace the pcm. however, this vehicle has had 3 pcm's since it was new (before we purchased it.) so im quite sure there is a wiring problem that is causing the pcm to toast itself. so before i replace it with a new one i want to check every wire for shorts to ground. but i dont have accurate wiring diagrams of the pcm circuit so i have no clue what im stabbing at with my meter. i do know how to do this, i just dont have a schematic to help me. can anyone out there hook me up witha complete wiring diagram in a pdf file or even a website that i can get it for free. i know its asking alot, but im in a major bind here. the car is taking up space on my friends lift and my father is ready to torch his car. thanks in advance -jon
p.s. if need be you can email me at [email protected]

[REAL Bob Johnson]

How bought going to any GM dealer walking into the shop like you know what your doing and ask one of the tech's for some help in about 5 minutes he can pull up the info on the computer and print any wiring diagram you want.

[OHCbird]

go to LS1tech or corvetteforums; they have PCM pinout links. My guess is that you went from year-to-year & maybe have the + going into the wrong terminal.

[EFI69Cam]

Make sure you have a 1999 or 2000 PCM. The 97-98 and 01-04 are different from the 99-00. Do you have access to another 1999-2000 vehicle you could plug the suspect PCM into?

[protour_chevelle]

Make sure you have a 1999 or 2000 PCM. The 97-98 and 01-04 are different from the 99-00. Do you have access to another 1999-2000 vehicle you could plug the suspect PCM into?

Yup, Pinouts are different for 97-98 ECU's to the 99+...

-Matt

[dgumoe]

allow me to clarify. the car was running when it went in the shop. it had a horrendous rod knock. so we swapped engines. we did NOT change pcm's. something got disturbed in the reassembly or dissassembly that is causing this short. i did manage to get pin layouts so once again this weekend ill be traveling to tampa to do some diagnostics. woohoo

[protour_chevelle]

Stock vette too? The GM harness's are stupid proof to be perfectly honest once they are hooked up correctly the first time IE OEM or after engine/harness swap into something else.

-Matt

[gEtyOpAPiOn]

well my pcm took a 20amp fuse ...make sure the fuse is not too small for the pcm