XC90 loosing power then regains it after blowing out dark reek.
 

On board computer saying that my car has airbag service light on. Doesn't bother the driving at all now it was fine yesterday and then today I driver it about 40 mile round trip and the power was jumping little bit ( Like it was hunting to find a gear) it was in 5th load of black smoke come out a few times into my local local garage plug the snap on computer into it and says there a problem with the gearbox control module, no lights on the dash so the garage owner says take it a good drive see if it will blow whatever in there out. So here Iam asking the Volvo community PLEASE HELP this bloody thing as cost me 1500 in the last month.