Troubleshooting - Carrier 40MBCQ Installation Instructions Manual

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 consists of two LEDs (Red and Green) on the
outdoor unit board and is limited to a few errors.
INDOOR UNIT DIAGNOSTIC GUIDES
OPERATION LAMP
☆
1 time
☆ 2 times
☆4 times
☆5 times
☆6 times
☆7 times
☆8 times
☆1 time
☆2 times
☆3 times
☆4 times
☆5 times
☆6 times
☆7 times
☆8 times
☆9 times
☆10 times
☆1 time
☆2 times
☆3 times
☆4 times
☆5 times
☆6 times
☆7 times
☆8 times
For additional diagnostic information, refer to the Service Manual.
Table 8—Indoor Unit Diagnostic Guides
TIMER LAMP DISPLAY
X E0
X E1
X E3
X E4
X E5
X EC
X EE
O F0
O F1
O F2
O F3
O F4
O F5
O F6
O F7
O F8
O F9
☆
P0
☆
P1
☆
P2
☆
P3
☆
P4
☆
P5
☆
P6
☆
P7
O (light) X (off) ☆ (flash)
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 on the indoor unit are listed in
Table 8.
LED STATUS
Indoor unit EEPROM error
Communication malfunction between indoor and outdoor units
Indoor fan speed has been out of control
Indoor room temperature sensor T1 open circuit or short circuit
Evaporator coil temperature sensor T2 open circuit or short circuit
Refrigerant leakage detection
Water-level alarm malfunction
Current overload protection
Open circuit or short circuit of outdoor ambient temperature sensor T4
Open circuit or short circuit of condenser coil temperature sensor T3
Open circuit or short circuit of Compressor discharge temperature sensor T5
Outdoor unit EEPROM error
Outdoor fan speed has been out of control
T2B sensor error
Lifting-panel communication error
Lifting-panel malfunction
Lifting-panel is not closed
IPM malfunction
Over voltage or over low voltage protection
High temperature protection of compressor top
Outdoor low temperature protection
Inverter compressor drive error
Mode conflict
Compressor low-pressure protection
Outdoor IGBT temperature sensor error
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