Returning to your diagnostic help regarding the permanently 'on' dashboard light and the possible cure touched on earlier by another post. Eliminating the presumed dodgy passenger seat connector by snipping the wires and soldering them together turns out to not be an option at least not on my '05 motor. Here's why.
The 'cable connector' under the passenger seat is no such thing, as I found out when I pulled it apart - it is in fact a 'first inertia switch' first-inertia-switch.jpg
- I'm guessing this will be for the seat belt pre-tensioners rather than the trigger for the airbag squib.
When I removed it, I put a meter across the three terminals labelled, NO, blank and NC. To my surprise the centre pin did not short to either the left or the right - but those two shorted to each other
Mindful of your instruction about diagnosing a poorly ACU in the footwell, I gave this 'inertia switch' a good shaking, and sure enough it started to rattle loudly - like a spraycan of paint would. Now, when I put the meter across the pins I get a good short across centre to NO and nothing across centre to NC (or NO to NC). Surely this is the exact opposite of how the switch should work -or am I confusing a switch with a relay. NO-and-NC.jpg
The fact that a good shaking produced a different signal path, would explain a lot and potentially solve the whole problem, were it not for the fact that the inertia switch, if my assumption that it is merely the seat belt pretensioner is correct, is not part of the airbag system and would not cause the dashboard light to stay on. Or would it?