Carrier 40GXQ - Manual (Page 11)

11
TROUBLESHOOTING
This unit has onboard diagnostics. Error codes will appear on the LED display on the front panel of the indoor unit in place of the
temperature display. Error codes are also displayed on the outdoor unit microprocessor board with colored LED lights. The table below
explains the error codes for both units.
38GXC/GXQ -- 40GXC/GXQ 009--024 Diagnostic Codes
Equipment Fault
Code Displayed
on Indoor Unit
Front Panel
LED Display on Outdoor Unit Board
Possible Cause
Green
LED
Number
of Flashes
Red
LED
Number
of Flashes
Yellow
LED
Number
of Flashes
Freeze Protection, Indoor Coil E2 4 3
Low Refrigerant Charge, Blocked Indoor Air
Flow, or Dirty Air Filter
High Compressor Discharge Temperature E4 7
Low Refrigerant Charge, Blocked Capillary,
or High Ambient Temperature
Low Voltage Protection E5 5 Low Voltage
Communication Error E6 0 Wiring Error, or Communication Failure
Indoor Air Temperature Thermistor F1 Bad Connection, or Sensor Failure
Indoor Coil Temperature Thermistor F2 Bad Connection, or Sensor Failure
Outdoor Air Temperature Thermistor F3 6 Bad Connection, or Sensor Failure
Outdoor Coil Temperature Thermistor F4 5 Bad Connection, or Sensor Failure
Compressor Discharge Line Thermistor F5 7 Bad Connection, or Sensor Failure
Defrost H1 2 Unit going through normal defrost cycle
Compressor Overload Protection H3 8
Low Refrigerant Charge, Blocked Capillary,
or Compressor Motor Failure
Compressor Over Current Protection H4 6
High Ambient Temperature, or Loss of
Condenser Airflow
IPM Module Protection H5 4
Loss of Cooling to Heat Sink, High Ambient,
Low Voltage, or Bad Connections
38/
40GX
C
(Q
)