ECU reset will only work if the fault is past and not current. It is cause by a design fault (the terminals inside are not tight enough so the resistance goes up and ECU register an open circuit). The cheapest (and the bullet-proof) solution is to cut the connectors out of the circuit and just soldering the wires together (make sure wires are not swapped), but you will need to cut/re-solder them if you need to remove the seats for any reason.