Error Codes - Lennox MMA018SM4 Service Manual

20. Error Codes

The error code display is located on the main controller board of all multi-zone outdoor units.
Table 10. MLB and MPC Multi-Zone Outdoor Unit
Error Codes
Display Malfunction and Protection Indication
Communication malfunction between indoor and
EL01
outdoor units.
Capability mismatch between indoor unit and outdoor
FL14
unit
EC50 Outdoor temperature sensor error.
EC51 Outdoor EEPROM error.
EC52 Condenser coil temperature sensor (T3) malfunction.
EC53 Outdoor ambient temperature sensor (T4 ) malfunction.
Compressor discharge temperature sensor TP is in
EC54
open circuit or has short circuited
EC55
Outdoor IPM module temperature sensor malfunction
EC56 Outdoor T2B sensor error.
EC57 Refrigerant pipe temperature sensor error.
Outdoor DC fan motor malfunction/fan speed out of
EC07
control.
EC71 Over current failure of outdoor DC fan motor.
EC72 Lack phase failure of outdoor DC fan motor.
PC00 Inverter module (IPM) protection.
PC02
Top temperature protection of compressor.
PC06 Discharge temperature protection of compressor.
PC08
Outdoor over-current protection.
PC0A High temperature protection of condenser.
PC0F
PFC module protection.
PC0L Low temperature protection of outdoor unit.
PC10 Outdoor unit low AC voltage protection.
Outdoor unit main control board DC bus high voltage
PC11
protection.
Outdoor unit main control board DC bus high voltage
PC12
protection / 341 Machine Check Error (MCE) error.
PC30 System high pressure protection
PC31 System low pressure protection
Table 10. MLB and MPC Multi-Zone Outdoor Unit
Display Malfunction and Protection Indication
Communication error between outdoor main chip and
PC40
compressor driven chip
PC42
Compressor start failure of outdoor unit
PC43
Outdoor compressor lack phase protection
PC44
Outdoor unit zero speed protection
PC45
Outdoor unit IR chip drive failure
PC46 Compressor speed has been out of control
PC49
Compressor over-current failure
PCA1 Condensation protection of refrigerant pipe
PH90 High temperature protection of Evaporator
PH91
Low temperature protection of Evaporator
LC06
High temperature protection of Inverter module (IPM)
84
Error Codes