SRS lamp - is how quickly it relights useful?

Hi The airbag lamp on my 2001 scenic goes out after 3 seconds and then relights after a total of 10 and stays on. However if I disconnect either seatbelt tensioner it relights after a total of about 6 seconds.

This makes me wonder if the timing of the light coming back on is an indicator of what/where the fault is? And if so does anyone know what 10 seconds means?!

Also what is the official life of the components? Are they ok for 13+ years or do Renault recommend replacement?

With thanks Tim