Carrier 38QUS012D8S Service Manual page 112

2.3 Outdoor Unit Malfunctions
For 24K~60K:
Display
E1 Communication malfunction between indoor and outdoor units
F0 Overcurrent protection
F1 Ambient temperature sensor (T4) malfunction
F2 Outdoor heat-exchanger temperature sensor (T3) malfunction
F3 Discharge temperature sensor (T5) malfunction
F4 Outdoor EEPROM malfunction
F5 Outdoor fan speed malfunction
P0
IPM module protection
P1 DC voltage too high/too low protection
P3 Ultra-low ambient temperature protection
P4 Compressor rotor position protection
J0 Evaporator high temperature protection
J1 Condenser high temperature protection
J2 High discharge temperature protection
J3 PFC module protection
J4 Communication error between outdoor main chip and compressor driven chip
J5 High pressure protection
J6 Low pressure protection
P7 IGBT sensor malfunction
J8 AC power input voltage protection
In low ambient cooling mode, the LED displays " LC" or alternates between running frequency and "LC" (each
appears for 0.5s).
Electrical Control System
Malfunction or Protection
Troubleshooting
110