Hi, This message came up today.
I have an offroad pack, and now the dial on the right for the diff lock is not working.
When I start the car, the light on the dial comes on and then car bleeps and light goes off, then message is displayed.

any ideas pls?

 

I’ve had the same issue occur to mine today. I have a GL420. Did you ever suss out the cause?

I’m going to try something basic tonight which is charge the battery as I found a post pointing towards the solenoid. The GL’s seem to be pretty fussy about electrical charge of the battery an I hope this is it.