RDC6585G controller constantly touches the pressure limit switch when turned on

Check the status of the limit switch and check if there is any physical damage to the pressure limit switch, whether it is stuck by debris, has poor contact, or loose wiring.
Manually trigger the test by manually pressing the lower limit switch, and then observe whether the corresponding limit signal changes on the diagnostic interface of the control system. If there is no change, it indicates that the switch or circuit is damaged.

Check if the connection between the limit and the motherboard is normal.