Carrier 38MFQ - Troubleshooting

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TROUBLESHOOTING
For ease of service, the systems are equipped with diagnostic code
display LEDs on both the indoor and outdoor units. The outdoor
diagnostic display is two LEDs (Red and Green) on the outdoor
unit board and is limited to very few errors. The indoor diagnostic
display is a combination of flashing LEDs on the display panel or
the front of the unit. If possible, always check the diagnostic codes
displayed on the indoor unit first.
The diagnostic codes displayed in the indoor and outdoor units are
listed in the tables below.
INDOOR UNIT DIAGNOSTIC GUIDES
Operation Lamp Timer Lamp Display Failure Mode
☆ 1time X E0 Indoor unit EEPROM parameter error
☆ 2times X E1 Indoor / outdoor units communication error
☆ 3times X E2 Zero-crossing signal detection error
☆ 4times X E3 Indoor fan speed has been out of control
☆ 5times X E4 Indoor room temperature sensor is open circuit or short circuited
☆ 6times X E5 Evaporator coil temperature sensor is open circuit or short circuited
☆ 2times On F1 Outdoor temperature sensor is open circuit or short circuited
☆ 3times On F2 Conden ser coil temperature sensor is open circuit or short circuited
☆ 4times On F3 Compressor discharge temperature sensor is open circuit or short circuited
☆ 5times On F4 Outdoor unit EEPROM parameter error
☆ 1times ☆ P0 IPM malfunction or IGBT over-strong current protection
☆ 2times ☆ P1 High or low voltage low voltage protection activated
☆ 5times ☆ P4 Inverter compressor drive error
☆ = Flashing, X = Off
For additional diagnostic information, refer to the Service Manual
OUTDOOR UNIT DIAGNOSTIC GUIDES
Green LED Red LED Failure Mode
On X Standby, normal
X On Operation, normal
On On High/Lowvoltageprotectiononcompressorterminal
On ☆ EEPROM error
X ☆ Compressor’s speed is out of control
☆ On Zero---crossing signal detection error; lack of phase; synchronization error
☆ X IGBT or Module protection
☆ ☆ Communication error
☆ = Flashing, X = Off
For additional diagnostic information, refer to the Service Manual