LG Mini-Split Code CH43
Soft lockoutShown as: Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 3 times
High pressure sensor is disconnected or shorted out. The discharge-side pressure transducer is not reporting a valid signal.
Manual wording: “High pressure sensor is disconnected or has shorted out”
Documented for: All LG residential mini-split outdoor units fitted with pressure sensors
Likely causes, most common first
- Bad wiring of the pressure sensor
- Bad pressure sensor
What you can safely check yourself
- Turn the system off at the breaker for three minutes and back on
When to call a technician
Pressure transducers are mounted on the refrigerant circuit. Replacement is technician work.
A LG mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- MULTI F / MULTI F MAX Outdoor Unit Installation Manual (LG Electronics U.S.A., Inc., Multi F and Multi F MAX multi-zone heat pump outdoor units (LMU series) with standard wall-mount, Art Cool, cassette and ducted indoor units) · checked 2026-08-25
- Single Zone Four-Way Ceiling-Cassette Installation Manual (LG Electronics U.S.A., Inc., Single-zone four-way ceiling cassette indoor units with LUU090HV through LUU420HV outdoor units) · checked 2026-08-25
- Convertible Mid-Static Ducted LGRED Degree System Installation Manual (LG Electronics U.S.A., Inc., LGRED single-zone convertible mid-static ducted indoor units with LUU180HHV / LUU240HHV outdoor units) · checked 2026-08-25
- Room Air Conditioner SVC Manual (General) - Trouble Shooting Guide with Error Code (LG Electronics, All LG single-zone room air conditioner / mini-split chassis (SW, SB, SC, S4, S5, SH, SA, SJ, SK)) · checked 2026-08-25