When an LG air conditioner displays an error code, something has occurred in the system that limits full functionality. The majority of error codes signal a problem that requires servicing, but a few error codes simply indicate that the unit is on a restricted setting.
Since LG air conditioners come in a variety of configurations, the error codes each system might display vary, and users should refer to their manuals for a list of errors specific to their particular model. The error codes are, however, standardized among LG air conditioners, so two different models displaying the same error code are probably suffering from similar issues.
Error codes on LG air conditioners are assigned either a number or two-letter combination, each indicating a different issue. On window and portable units, the number is preceded by an E, such as with "E1," which indicates that the temperature sensor has failed. Other configurations might display letter codes such as "CE," which indicates that a current error has occurred that affects the unit's compressor.
Additionally, codes might also display for system states that aren't otherwise errors. For example, if a unit displays the code "CL," this indicates that the system is on child lock, which inhibits full functionality of the system.