You mentioned it was flashing the 3, 7 code. On mine it was the yellow connector under the passenger seat that someone mentioned. It where the side air bag would plug in if there was one. It's capped off with a real small value resister inside and the contacts frequently get dirty and some electrical spray cleaner can help. On 2 doors like mine, it seems to be common that the wires break 'cause when you move the seat up the cable is exposed and easy to step on. I had to jury rig mine because it's impossible to get the pins out of those connectors (safety features). But if your's works after cleaning it, I'd wrap it in electrical tape to keep dust out and tuck it under the carpet instead of hanging it in the bracket under the seat.
