Daewoo Air Conditioner Error Code CODE3

CODE3 indicates that the outdoor ambient temperature sensor has been detected as either open circuit or short circuit. The control board cannot receive a valid temperature reading from the sensor and has shut the unit down as a result. The fault covers both a broken circuit and a collapsed short in the sensor or its wiring. The unit will not operate until the fault is resolved.

A power reset may temporarily clear the error code display, but CODE3 will return as soon as the system restarts and re-checks the sensor circuit. Because the fault reflects an actual electrical condition in the sensor or wiring, it will not resolve on its own without physical repair. Resetting without addressing the root cause will not restore normal operation.

If only the connector or wiring needs attention, repair costs may be minimal, covering primarily labor time. If the outdoor temperature sensor itself needs replacement, parts and labor costs typically range from around 50 to 200 dollars depending on your location and service provider. If the fault has caused control board damage, costs will be higher. Getting a diagnostic assessment from a qualified technician before purchasing parts is recommended.

Start by inspecting the outdoor sensor connector for corrosion, moisture, or loose terminals and reseat it if necessary. Then measure the resistance of the O/D sensor and compare it to the expected value for the current ambient temperature. If the reading is infinite or zero ohms, the sensor needs to be replaced. Also check the wiring harness for any visible damage between the sensor and the control board.

The unit will not operate while CODE3 is active, so there is no risk of running it in a damaged state. The system is designed to shut down completely when this fault is detected. There is no safety hazard to the home from the fault itself, but the unit should be repaired before attempting to restore operation.