93 cadillac eldorado with 4t80e trans. had a 3.11 diff ratio (option code fv3) Scrapyard sent me a 4t80e with a 3.71 (option code fv4) diff ratio. now it is throwing code p086 for unrecognized/uncalculated ratio . what to do? can the pcm be reprogrammed to handle the new transaxle?