Hi 
The fault01217indicates that the Igniter resistance measured by the Airbag controller exceeded the maximum allowable spec - the Upper Limit. This would occur due to a bad connection.

Dtc 01217 - mean: Side Airbag Igniter; Driver Side (N199)
this failure is very common on this vehicle

Check Wiring/Connectors from/to Side Airbag Igniter, Front Driver Side (N199)
Check Side Airbag Igniter, Front Driver Side (N199) faulty
Check Measuring Value Blocks (MVB)

I fixed one of these last month. The owner had reclined the seat and the light came on, so I pulled the seat out and stripped it to get to the connector right up at the bag. There was a bit of a strain on the wire and a broken cable tie, so I disconnected and reconnected it, erased the code and all is good so far.