LG Refrigerator Error Code E rS

The E rS error code on an LG refrigerator indicates a fault with refrigerator temperature sensor 1, also called the refrigerator compartment sensor. The control system monitors this sensor continuously and triggers E rS when it detects a short circuit, an open circuit, or a resistance reading that falls outside the acceptable range. Because the main PCB uses this sensor's input to regulate cooling cycles in the fresh food compartment, a faulty or disconnected sensor can cause the refrigerator section to run too warm, too cold, or cycle erratically.

The sensor itself is a negative temperature coefficient (NTC) thermistor, meaning its resistance decreases as temperature rises. The main PCB reads this resistance through connector CON7, specifically pins 19 and 20. If the measured resistance is too high, too low, or effectively infinite (open circuit) or zero (short circuit), the board interprets the reading as out of range and triggers the fault code. Wiring damage, corrosion at the connector, or a failed thermistor are all capable of producing these out-of-range conditions.

Diagnosis should begin at CON7 pins 19-20 on the main PCB, checking for loose, corroded, or damaged connections before condemning any component. If the connector checks out, the thermistor itself should be tested with a multimeter to confirm its resistance matches expected values for the current compartment temperature. Only after ruling out wiring and connector issues should the sensor or the main PCB be considered for replacement.