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Error code reference

LG Refrigerator Error Code Freezer 1st Digit b

Damper heater error

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What the Freezer 1st Digit b error code actually means

Your LG refrigerator has detected that a small heating element near the damper (an airflow control flap between the freezer and refrigerator sections) is not receiving power properly due to a wiring problem. This usually means a wire has come loose, disconnected, or broken somewhere between the control board and that heater. Left unrepaired, ice buildup at the damper could affect how well your refrigerator cools.

Diagnostic procedure

The full Freezer 1st Digit b procedure

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1
First diagnostic step
Unplug MAIN PCB CN90 from PCB, check resistance between #1 (BLACK) and #2 (BROWN); should read 140~160 Ohm.
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Most common causes of Freezer 1st Digit b

Ranked by how often they cause this code
  1. 1Slipped-out connector at CN90
  2. 2Open contact within the wiring harness
  3. 3Cut or broken wire
  4. 4Failed damper heater element
  5. 5Faulty main PCB

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Questions people ask about Freezer 1st Digit b

What does Freezer 1st Digit b mean on a LG refrigerator?
The Freezer 1st Digit b code indicates a damper heater open-circuit error. The control board has detected that the damper heater circuit, measured at connector CN90 on the main PCB, is not showing the expected resistance of 140 to 160 ohms. This points to a disconnected, broken, or open-contact condition in the heater wiring or the element itself.
Is it safe to keep using my LG refrigerator while this error is active?
Short-term use is generally possible, but the damper heater plays a role in preventing ice buildup at the damper assembly, which regulates airflow between compartments. Over time, ice accumulation could impair cooling performance in both the freezer and fresh food sections. Prompt repair is recommended to avoid potential food spoilage or secondary damage.
How much does it cost to repair the Freezer 1st Digit b error on an LG refrigerator?
Repair costs vary depending on the root cause. If only a connector needs reseating, there may be no parts cost, though a service call fee typically runs between $75 and $150. Replacing a wiring harness or damper heater element generally adds $30 to $120 in parts, plus labor. If the main PCB is at fault, board replacement can range from $150 to $400 or more depending on the model.
How do I fix the Freezer 1st Digit b error on my LG refrigerator?
Start by unplugging the refrigerator and disconnecting connector CN90 from the main PCB. Measure resistance between pin #1 (BLACK) and pin #2 (BROWN) using a multimeter. If you read infinite resistance or a value well outside 140 to 160 ohms, trace the wiring from CN90 to the damper heater, looking for loose connectors, broken wires, or a failed heater element. Repair or replace whichever component is faulty.
Will resetting my LG refrigerator clear the Freezer 1st Digit b error code?
A power reset may temporarily clear the displayed code, but the error will return if the underlying open-circuit fault in the damper heater wiring or element has not been corrected. The control board will re-detect the fault the next time it checks the CN90 circuit. A permanent fix requires diagnosing and repairing the faulty wiring, connector, or heater element.

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