I just had this fixed my my 350 with 125k on it. Called up lexus customer service and they offered to pay for exactly half of the repair cost down to the penny...actual harness replacement came in slightly less, so I ended up paying about $1600. As other threads state, dealer couldn't reconnect my nav bypass, but no biggie.
When my car was in, they said there were actually 2 codes. One was directly related to the harness, the other might be because of the harness, and if replacing the harness didn't clear the code, it could have meant air bag sensors or air bags all in the driver area. Luckily the harness seemed to clear it.