Daewoo Air Conditioner Error Code 2

Error code 2 on a Daewoo air conditioner indicates a fault in the indoor coil thermistor circuit, specifically an open or short circuit condition detected in the evaporator temperature sensor or its associated wiring. The indoor coil thermistor is a negative temperature coefficient (NTC) resistor that the control PCB monitors continuously to track evaporator coil temperature. This data is critical for regulating compressor operation, preventing coil freeze-up, and managing overall system performance. When the PCB reads a resistance value outside the expected range for the thermistor, it interprets this as a sensor or wiring failure and triggers error code 2.

The two primary failure modes are an open circuit, where the resistance reads extremely high or infinite (typically caused by a broken wire or failed sensor element), and a short circuit, where resistance drops near zero (caused by insulation breakdown or a shorted sensor). Both conditions produce temperature readings that fall outside normal operating parameters. The control board cannot distinguish a genuine extreme temperature from a faulty sensor, so it shuts down normal operation to protect the system.

Diagnosis should begin at the thermistor connector and wiring harness between the sensor and the control PCB. Connectors can loosen from vibration, corrode over time, or develop intermittent contact faults. The solder joints on the PCB where the thermistor circuit terminates are also a known weak point, particularly if the board has been exposed to moisture or thermal cycling stress. A technician should visually inspect the connector seating, check wiring continuity, and verify the thermistor resistance value at room temperature against the specification chart for the unit.