The W123 Vacuum Lock system was a cinch to troubleshoot and repair--usually the problem was the door diaphragms rotting out or not enough vacuum because of a vacuum leak somewhere like on the Transmission modulator. On my 85 300D I got the thing fixed so well, the system will operate even two or three cycles even after the car has been sitting for a month.

The W124 is a different animal. It uses electrical pressure sensors and has its own vacuum pump I think. What is WIERD is mine actually came to LIFE for a two weeks and worked well, then stopped working.

Any Hints?