Looking for some advice regarding my 2014 SDV8 L494.

I've not been driving her much lately out of fear as it's been in and out of the garage multiple time already this year. Most recently it's had a new altenator & battery fitted.

Went out this morning and now getting the 'E-Diff not available' aswell as the drivers airbag warning light. Is it likely that both these control modules need replacing? Has anyone had to replace these & if so what was the aproximate cost without labour?

Have you had the headlight earth straps sorted as they cause these sort of issues ?

I'm not aware that's ever been done.

Is it something easily check myself, do I need to remove the headlight to check?

If I choose to leave the E-Diff warning light on what's the worst that can happen?

I wouldn’t be hasty in condemning the modules. First off, get a scan for fault codes with a decent diagnostic tool. Could be something totally unrelated or it could be something like the main grounds behind the front wheel arch.