15 minutes is usually sufficient for the reserve power to dissipate, although I will concur that it is not guaranteed to be enough time for that to happen. As well, after re-reading my first reply, I see that I did point out that the fuse should be pulled:
quoting myself here:
"Pull the negative battery and fuses for the SIR as an additional safety, then wait 15-20 minutes for the backup power in the SIR system to discharge."
Admittedly I did not offer a specific fuse by number or function name. This is where I fell short. Further, after thinking about it some more simply pulling the fuse may not immediately disable the SIR as this circuit is feeding the 12V to the SIR [SDM] module, and the reserve deployment power is integral to the module (after the fuse so to speak) so one either has to:
1. Still wait 15 or more minutes for discharge of reserve power -OR-
2. find and disconnect harness(es) to the inflator modules to isolate them entirely from the SDM (sensing and diagnostic module, which contains the reserve power) which is the ideal means of eliminating the chance of blowing a bag off while tinkering around. I know I did this when I pulled my steering wheel, simply no excuse to take chances.
So, I still stand corrected as I can see where my posted procedure was not outlined as completely as it should have been.
In any case, I wanted to clarify this all so nobody reads and follows inadequate advice while working on something as touchy as the SIR system. I'd not want to be the cause of someone doing hundreds (or thousands) of dolllars in damage on account of something I typed in haste.
Of course this being a more or less public forum, anything said here should be treated cautiously, especially where safety critical items are being discussed. Always verify/double check information as even the best of us are prone to make mistakes.