Carrier 38QUS012D8S Service Manual page 99

6：Lack of phase
7：DC voltage too low
8：Communication fault
9：Parameter fault
10：L3 Current limited
11：L5 Voltage limited
12: Target speed cannot be met during the static pressure calculation process.
For other models:
If the indoor fan speed is lower than 300 RPM for 50 seconds or more, it shuts off and restarts in 30 seconds.
If this happens 3 times, the unit stops and the LED displays the failure code.
Electrical Control System
Electrical Control Function
97