Skip to main content
Error code reference
LG Refrigerator Error Code R1 R2 R3 R4 (blinking pattern 2)
Faulty D sensor - The defrost sensor is open or short circuited, no defrost is performed.
SourceLG Electronic Refrigerator - Service Manual: G392/G432 Seriesp. 18
Diagnostic procedure
The full R1 R2 R3 R4 (blinking pattern 2) procedure
Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.
MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check defrost sensor resistance and voltage at Point B (normal 0.5V-4.5V, short-circuited 0V, open 5V). Replace sensor if faulty.
SourceLG Electronic Refrigerator - Service Manual: G392/G432 Seriesp. 18
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
Unlock R1 R2 R3 R4 (blinking pattern 2) procedure $9.95
Or subscribe: $29/month for all codes plus Max diagnostics, with 70 Max messages a day. Plus applicable tax.
75,000+ service documents · 20,000+ error codes · 100+ brands
Get Started$29/month · Cancel anytime · Or $9.95 3-day pass · Plus applicable tax