LG Refrigerator Error Code R1 R2 R3 ON

The R1 R2 R3 ON error indicates that the ambient room temperature (RT) sensor has an open or short circuit. This sensor measures the temperature of the air around the refrigerator and feeds that data to the control board. When the sensor signal falls outside acceptable parameters, the refrigerator displays this error to flag that the ambient temperature reading is unreliable. A technician should check the sensor and its wiring to diagnose the root cause.

The refrigerator may continue to run with this error active, but it cannot accurately factor in ambient temperature when regulating cooling cycles. This could result in reduced efficiency or inconsistent cooling performance over time. It is advisable to address the fault promptly to prevent potential food spoilage or additional strain on the compressor.

A power reset may temporarily clear the error display, but if the underlying sensor or wiring fault still exists, the error will return once the control board runs its diagnostics again. A reset is useful for confirming whether the fault is intermittent or persistent, but it does not repair a failed sensor or damaged wiring. The root cause must be corrected for the error to clear permanently.

A knowledgeable DIYer can attempt basic diagnostics such as inspecting the RT sensor wiring harness for visible damage, checking connector pins for corrosion, and reseating connections. Testing the sensor with a multimeter requires some technical comfort but is straightforward. If the sensor itself has failed, replacing it is a relatively accessible repair, though accessing the sensor location varies by model.

If the fix is simply reseating a connector or cleaning corroded pins, costs may be limited to a service call fee, typically in the range of $75 to $150. If the ambient RT sensor needs replacement, parts generally range from $15 to $50, with total repair costs including labor falling between $100 and $250 depending on the technician and region. Control board replacement, if required, is more expensive, often ranging from $200 to $450 or more.