Okay. Time to back up. If it was a DCL fault/problem, the MCE controller would shut down due to a fault (no DPM input).
So; why does the door open half-way, then immediately close without effect from the detector or door open button? No door zone input!
The MCE LQUT and L(something) are notorious for having poor hall-effect sensors. Mostly, they are just loose. They require tightening or replacing. Also, the factory wiring on the landing systems leaves something to be desired. Check for wires that are crimped on the insulation.
First, though, I should ensure that the rascal is not flopping in the breeze. If the triac goes, the fault would be consistent.
Hope this helps. Schindler, Toronto, Canada.
