Agree with Stephen's comments. There are spare connectors under seat on some models - what year/model do you have?
Has the light just come on or has it been on for awhile?
Sometimes it can just be caused by weight on the passenger seat, if I am carrying anything heavy on this seat, 8KG dog for example, it goes on and off as she moves around so I tend to buckle the seatbelt to avoid it. You really need to check it with a code reader, where are you based in case there is a member near you with one.
1998 Roadster 2.8.Agree with Stephen's comments. There are spare connectors under seat on some models - what year/model do you have?
Has the light just come on or has it been on for awhile?