42TroubleshootingFault diagnosis by remote controllerIn the ARC452A series, the temperature display sections on themain unit indicate corresponding codes.1. When is held down for5 seconds, a “ ” indication flashes on thetemperature display section.2. Press repeatedly until a continuousbeep is produced.• The code indication changes as shown below, and notifieswith a long beep.NOTEFault diagnosis.CODE MEANINGSYSTEM00 NORMALUA INDOOR-OUTDOOR UNIT COMBINATION FAULTU0 REFRIGERANT SHORTAGEU2 DROP VOLTAGE OR MAIN CIRCUIT OVERVOLTAGEU4 FAILURE OF TRANSMISSION (BETWEEN INDOOR UNIT AND OUTDOOR UNIT)INDOORUNITA1 INDOOR PCB DEFECTIVENESSA5 HIGH PRESSURE CONTROL OR FREEZE-UP PROTECTORA6 FAN MOTOR FAULTC4 FAULTY HEAT EXCHANGER TEMPERATURE SENSORC9 FAULTY SUCTION AIR TEMPERATURE SENSOROUTDOORUNITEA COOLING-HEATING SWITCHING ERRORE1 CIRCUIT BOARD FAULTE5 OL STARTEDE6 FAULTY COMPRESSOR START UPE7 DC FAN MOTOR FAULTE8 OVERCURRENT INPUTF3 HIGH TEMPERATURE DISCHARGE PIPE CONTROLF6 HIGH PRESSURE CONTROL (IN COOLING)H0 SENSOR FAULTH6 OPERATION HALT DUE TO FAULTY POSITION DETECTION SENSORH8 DC CURRENT SENSOR FAULTH9 FAULTY SUCTION AIR TEMPERATURE SENSORJ3 FAULTY DISCHARGE PIPE TEMPERATURE SENSORJ6 FAULTY HEAT EXCHANGER TEMPERATURE SENSORL3 ELECTRICAL PARTS HEAT FAULTL4 HIGH TEMPERATURE AT INVERTER CIRCUIT HEATSINKL5 OUTPUT OVERCURRENTP4 FAULTY INVERTER CIRCUIT HEATSINK TEMPERATURE SENSOR1. A short beep and 2 consecutive beeps indicate non-corresponding codes.2. To cancel the code display, hold the down for 5 seconds. The code display alsocancel itself if the button is not pressed for 1 minute.