One problem related to warning light on has been reported for the 2012 Mercedes Benz GLK350. The most recently reported issues are listed below.
After just parking the vehicle but before getting out - the drivers headrest "exploded" and pushed my head toward the steering wheel. When driving the vehicle home the message center said problem with the driver front airbag and the passenger front airbag and the warning light was on. The next day I drove to the dealer and they pushed the headrest back together but could not get the message removed and said it would need diagnostics. I drove away with the messages still coming on intending to make an appointment for diagnostics. Returned to have the message center stop showing messages and the dealer was able to correct the issue saying it was just a blown fuse causing the problem. I drove the car approx. 30 min the next day and then 2 and 1/2 hours the following day and while driving on highway at full speed the headrest "exploded" again throwing my head to the steering wheel and I was able to narrowly avert causing an accident. I drove straight to the dealer. They pushed the headrest back in and wanted me to leave. I did not want to drive the car without someone checking the problem so they kept the car. The message center is now not indicating a problem and because the person pushed the headrest back together they are unable to see a problem. Warranty is up on the vehicle but feel this is a potential fatal safety issue to report.