Airbag light and central locking click coincide

[woz]

2012 Clio 3 1.2 Tce
Very low miles

While driving (I hadn't hit anything) the Airbag warning light came on along with a brief click from the doors.
I had a scan done at a local garage on a Maxi Diag (my obd won't show airbag codes it's rubbish)
" DF043 Active Passenger 's lateral Airbag Sensor Electronic fault in sensor" - no other codes showed. I think from diagrams that sensor is in B pillar behind passenger seat?? but I'm not convinced for reasons below that the sensor is a fault because of the central locking clicks issue.
When I switch on the ignition I now get a brief click from central locking along with the light on the central locking button illuminates VERY briefly, it never did that before this fault appeared.
It then goes through checks and maybe 20 secs later usually while displaying oil check, with a brief click from the doors the airbag light comes on.
It behaves slightly differently if the central locking is engaged -the airbag light was on immediately ignition is on. The two are somehow linked
I've looked through the wiring diagrams , and there are very few places where central locking and airbag components might coincide.
The cost of a main dealer trying to fix this (unless it really is just the sensor, (which I am prepared to change if I can get a used one with the same number) could run into 4 figures!
(I've also convinced myself that it's temperature sensitive because when it was very cold I'm sure it took longer for the airbag light to illuminate, but didn't get to test that repeatedly - dry joint? )

All thoughts welcome
Thanks.

[gooroo]

I know this is a year late but I thought I would mention the door click I think is a safety thing, if the car detects a fault with the SRS it automatically unlocks the doors, if you lock the doors and turn the ignition on wait for the SRS light to go out and then come back on it will unlock the doors.

Regards, Simon