Does anyone know what the purpose of this circuit was, was it a type of peak operation, or designed as a failure circuit if a hall call is stuck.

When you get a hall call XHC pulls in, dropping HC, this allows CC to start timing. Once in it pulls in CCX and CCY, and self holds.
Various contacts from the CC relay are in the doors cirucit, block UDR on both cars and block HJG on both cars.

Once all hall call are answered and XHC drops, it is supposed to time MGT and then drop CC, and the units go back to normal. Problem is this unit does not have the XHC(5_6) contact as shown on print, so MGT can't time. So eventually the units get stuck in lobby with doors open. It wont take car calls

This has happened twice recently. Occasionally the one of the cars will make a run, though I haven't looked into why.

Any insight will help me on my next visit. TIA