Tried to manually downshift from D, but the gearshift lever physically won't move left over to the 4 position. Worked just fine a month ago or so when I used the lower gears. Any ideas on what could cause this?

 

Anyone?

 

Is something blocking it? Take the wood trim off and see if you can find anything.

 

It is the gear selector switch. It is the locking mechanism for the shifter. My friend just had a the same problem with his S class. Turn off radio and air turn the key to position 2 and ease into the break slowly. Once you hear the click the lock will open. If this dosen't work the piece will cost around $500 or more.

 

Thanks for the suggestion.

There's definitely something weird going on with the shift interlock. I can shift out of park with/without the key with/without pressing the brake. It should only come out of park when both the key is in position 2 AND the brake is depressed.

Does the interlock normally control the D<-->4 shift? If not, perhaps this a matter of adjustment?