A 4-7 code is resistance in the driver seat pretentioner. Clean up the seat electrical connections, use dialectic grease on the terminals.
The pretentioner is mounted on the seat frame, infact your female belt bucket is attached to it. I'm lookin' for my pics, and a comparo shot between a "triggered" pretentioner and a good pretentioner. You need to remove the seats to access it, or remove the centerconsole(mabybe)...might as well remove the seats. BUt if your just doin' the dialetic grease your ok for no removal...the plug is located on the rear of the seat bottom.
What it does, as i understand it, is when it is triggered during an air-bag deployment, and it clinches down on the seat belt. the female seat belt end is built into the tensioner, and when it goes off, that female end is about half as tall.