GE Ice Maker Error Code ON/OFF and QUICK ICE LEDs blinking

When both the ON/OFF and QUICK ICE LEDs blink simultaneously on a GE ice maker, the control board has detected a harvest mode failure. The harvest cycle is the phase where the ice maker warms the evaporator plate just enough to release formed ice cubes into the bin. This process relies on the evaporator thermistor to monitor temperature and signal the control board when the ice has properly released. If the thermistor circuit reads outside its expected resistance range, the board flags the failure and triggers this blinking LED pattern.

The evaporator thermistor is a temperature-sensing resistor whose resistance changes in a predictable way as temperature rises or falls. When the control board detects that the thermistor is open (infinite or very high resistance) or shorted (near-zero resistance), it cannot trust the temperature readings needed to manage harvest timing. Rather than shutting down entirely, the ice maker defaults to a 5-minute timed harvest cycle as a fallback, allowing limited operation while the fault is active.

The most direct diagnostic step is to check the evaporator thermistor resistance with a multimeter. A reading that is extremely high, reads open, or reads near zero ohms confirms the thermistor has failed or its wiring circuit is compromised. Also inspect the wiring harness between the thermistor and the control board for pinched wires, corroded connectors, or loose terminals, as connection issues can mimic a faulty thermistor. If resistance is within specification, the control board itself may be misreading the signal and could require further evaluation.