OK, this is the
EVEN CHEAPER FIX, cost effectively nil if it is just the thigh pad sensor at fault!
Move the seat back and tilt the front up to gain access. Move the thigh support forwards as far as it will go.
Look underneath and you'll see a thin black cable sleeve that runs from the thigh support back under the seat, remove the cable tie to ease access.
Carefully cut open the sleeve open to confirm it contains the blue and white pair of wires for the occupancy sensor; trim back the sleeve to bare a good length of wire and cut through it nearer where it enters the pad so there's a decent length to work on emerging from under the rear of the seat.
Tape up or cable tie the spare wires going into the thigh pad, this part of the sensor is now inactive. Move the pad back now to make access easier.
Join the blue and white wires together at the end of the cable coming from under the seat.
I actually used a "choc-block" connector and small loop of wire, but that was for convenience of testing resistances. You could just strip off some insulation and crimp them together.
(I'll probably do that some time if the fix continues to work OK)
Tape or cable-tie out of the way and return seat to normal position.
Finally plug in your laptop running VCDS (or equivalent) and clear the codes from the Airbag Module.
All seems to be working normally so far......
I did do some vague resistance testing, as follows:
The thigh pad was open circuit when unloaded, pressed as hard as I could manage (in some places) I could get it down to maybe 20K ohms.
The main seat pad was in the "several K ohms" range when unloaded and dropped to maybe 200 ohms (IIRC, not sure exactly what range my meter was on) with my big fat backside on it.
I'll report back if there are any untoward developments.....