Lots of help available if you Google;
"Primera p12 airbag reset"
If you carry out procedure below you may have to try it a few times to get the hang of timing.
I have an intermittent airbag light problem and I have been successful. This works if its an intermittent problem with under seat connections etc.
(a) Switch OFF the radio & Ignition
(b) Turn Ignition ON (Position II)
(c) The airbag warning light will stay on for 7 seconds and then switch off - as soon as it does
turn OFF the ignition (within 1 second of the light switching off)
(d) Wait at least 5 seconds
(e) Repeat steps (a) to (c) two more times - this is important to make sure it registers with
different modules in the car
(f) Turn ON ignition, wait 2 seconds
(g) Switch OFF Ignition (Position 0) and wait 1 second
(h) Switch ignition back ON.
(i) Airbag light should now remain unlit as long as the fault(s) causing are also addressed
William, March 2013