Hi all Happy New Year

Had a call out to a Kelvin water chiller KRA120 A21301 providing cooling as part of a injection moulding machine. The customer has told me that they have had problems with refrigerant leaks in the past and that a leak was repaired 8 months ago. The system is on R407C and is standing at 6 bar. The controller is flashing up the fault code 1A. The only thing that will run is the pump, comp and fans do nothing. Any ideas what Fault 1A represents