jack0hearts

I had an electrical failure while jump starting one of my older rigs, which turned out after much frustration to be a bad ground connection. My truck starts and idles but is in "limp in" mode ie the od light flashes and it wont shift out of one gear. it also appears to only be running on a couple of cylinders. I've heard that some vehicles have an anti theft feature that disables a vehicle this way. Ive also been told that letting it set for a day or so with the battery disconnected can sort of reset the default setting in the ECM. Anyone have any info to support or refute these ideas?