on my 126 car there is a ~12 pin red plug in the passenger footwell, under the carpet. That disables the airbag.

Same on 103 124 cars, So it should be there on your diesel.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E