Ressurecting an old thread as a follow-up:
Finally got around to fixing my airbag intermittent light problem yesterday.
FSM said that disabling SIR system is as easy as: pull fuse, drop shields under dash, and unhook both airbag harnesses. Did that, and didn't have any later deployment problems.
Fiddled with yellow connector from sensor to brain unit (yellow connector tucked behind PCM) to ensure good connection.
Then unbolted front passenger seat. Didn't have a torx big enough to undo the "load rail" (long rail connected at same point as middle seat belt), but luckily I could just pivot the whole front seat upwards and backwards and lay it in the rear footwell without undoing that torx.
Removed trim, pulled up carpet and underlayment, and there was the brain unit. Luckily, no moisture or rust at all on floorpan or module. Made sure that connection was good and tight, then reattached the seats, reconnected the airbags, then replaced the dash trim and put the fuse back in.
None of the connections seemed loose, but at least one must have been, because the light hasn't come on again since.
Entire operation took about 90 minutes (including oxi-clean-ing some coffee stains under the seats!)
2004 Buick Lesabre Limited, Gran Touring; Bone Stock
1998 Buick Lesabre Limited, Gran Touring; Mods: Poly sway bushings/endlinks, Tru-Cool trans cooler, Thrasher shift kit (med), PLIM, front PEM; Mods in progress: Alot of stuff, but slowly...