Air bag light comes on when car started

drivers footwell engine side of ecu i have a yellow plug with two purple wires , i cannot find a socket, firstly does anyone know what this wire is for and secondly would this be the reason for airbag warning to come on.eddie

Welcome to the forums.
Sounds like its going to be the seat pad connector to arm the passenger air bag when the seat is occupied, perhaps the seat has been replaced?

This is the XJS forum.
You might find better info from the XJ6 list.

This is the xj list, Stephen? And ‘our’ Jaguars do not have air bags…

xj6 85 Sov Europe (UK/NZ)

Moving to the X300 list.