after driving for a 50 miles or so transmission goes into ist and wont change gears, whats causingthis
First check to see if there is any ATF in the transmission. If ATF is not up to the hash marks, add some ATF to bring the oil level to a normal operating position. Make sure the vehicle is on a flat and level place. If the transmission won't shift out of first gear, the gears may be broken or jammed. You had best find an automatic transmission specialist who can remove the transmission and repair it or trade it for a replacement/rebuilt/remanufactured one. There are many types of ATs, so be sure you have the correct model and the right person to deal with your problem. It will not be a cheap fix.
Yeah, I think you are supposed to get at least some traction at the other axle. Many subies have a limited slip clutch in the transfer case. Check out the specs for your car. If it has 3 open differentials, it would work as you described. Otherwise, something may be broken, worn out or turned off, etc.
Dynamic control kicks in when slippage has been detected on a wheel. The car does not know you that you are on ice, so it takes over to stop the slippage incorrectly. You will have to switch the drive to snow/ice mode(X-Mode) for the car to move correctly. Power to the power.
This is why Land Rover fit a lock to the central differential and traction control. I also have a locking rear differential on mine. Most AWD cars are not ment to be off roaders. They are not equipped for that sort if driving.
A common fault for non-shifting is a bad transmission valve body electrical plate. Have a dealer or other trusted shop familiar with the Benz 722.6 electronic transmissions diagnose to confirm.
