When the light stays on for two minutes then goes off it is warning of a non safety related failure. The arirbags will still work but could use a different strategy.
The most common problem here is the selt belt buckles. The crash profile for airbag deployment is changed based on whether or not the seatbelt is on. so, the controller wishes to know. The two positions engaged or disengaged looks to the controller as two different resistances. it is not open or closed. if it could accept open as an answer then a disconnected (broken wire) buckle would be an acceptable sensor response. To avoid this and provide diagnostics the resistance of an open buckle is 400ohms if I remember correctly.
If the controller sees anything but closed circuit or 400ohms it sets the light. AS a result the airbag is probably deployed in the strategy for a seat belt not connected.
Bosch Master, ASE Master, L1
33 years MB technician