Daewoo Air Conditioner Error Code LED 8s blink

The LED 8-second blink code on a Daewoo air conditioner signals a fault detected in one or more of three temperature sensor circuits: the room (ambient) sensor, the indoor coil sensor, or the outdoor coil sensor. These sensors are NTC thermistors that feed resistance-based voltage signals to the microcomputer (micom) so it can regulate operation. When the micom detects an input voltage outside the expected operating range on any of these sensor lines, it halts normal operation and triggers this blink sequence to protect the system from running on faulty temperature data.

The fault falls into one of two electrical conditions. An open circuit condition occurs when the sensor wire is broken, the connector is unplugged or corroded, or the thermistor element itself has failed with infinite resistance. In this state, the micom input voltage drops to the 0 to 0.3V range because the voltage divider circuit has no return path. A short circuit condition is the opposite: the sensor circuit is shorted to ground or across its leads, collapsing resistance to near zero and pulling the micom input voltage up to the 4.7 to 5.0V range. Both extremes are outside the valid temperature-representative voltage band and immediately register as a sensor fault.

Diagnosis requires checking the input voltage at the micom terminal for each sensor circuit and comparing it against those two threshold ranges. A reading below 0.3V points to an open condition in that sensor loop, while a reading above 4.7V points to a short. Once the faulting sensor circuit is isolated, technicians should inspect the wiring harness for damage, check connector seating and pin corrosion, and use a multimeter to measure thermistor resistance directly at the sensor body to confirm whether the fault is in the sensor itself or in the wiring between the sensor and the control board.