Error code reference

LG Air Conditioner Error Code 174

Failure of Sub1 constant speed compressor 1 operation - compressor locking, check valve leakage, or dielectric breakdown.

SourceLG Air Conditioner - Full Service Manual: LRNU/LRUN/LRUV Seriesp. 170, 239

LG codes LG air conditioner codes

Diagnostic procedure

The full 174 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

First diagnostic step

Check compressor operation when pressing magnetic switch; check check valve direction; measure insulation resistance.

SourceLG Air Conditioner - Full Service Manual: LRNU/LRUN/LRUV Seriesp. 170, 239

Unlock with pass

More steps, wiring diagram references, and verified part numbers

Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.

Unlock 174 procedure $9.95

Or subscribe: $29/month for all codes plus Max diagnostics, with 70 Max messages a day. Plus applicable tax.

Where this code is documented

18 manuals in the MyPros+ library document this code for LG air conditioner.

Models covered by the manuals that document this code

More models are covered than are listed here.

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

The full 174 procedure

Where this code is documented

Models covered by the manuals that document this code

Related LG air conditioner error codes