A PCC-1 can only be mechanically disabled with a contact closure, this is most often accomplished with a relay. A wire from the Disable pin to 1 side of a relay then back to the ground connection. Once this connection is made you can program the PCC-1 to disable by closing the relay
You should replace the LCDACC SL30NCL with a reed relay “604-501-0017 – 2 REED RELAY OUTPUT BOARD ASY” *219XTM due to the fact the normal relay does not handle the low voltage/current that is present to disable the PCC-1.
You will need a 2-wire red connector from the factory with wire inserted in both positions factory part # 101-003-0003 “CON AMP MTS 0.100IN 20POS 22 AWG F” to connect to the PCC-1 both wires can be connected to ensure you get the correct pin (only the top pin is active to disable the PCC-1).
A *220F4G “604-000-0024 – 2 REED RELAY SPDT ASSY” may be used instead of the *219XTM, this is a SPDT instead of the SPST.