The error codes window lists fault codes (error codes or DTCs) and readiness codes from the ECU.
Fault Codes
Fault codes are error codes from the Honda ECU, and usually indicate a problem with a sensor or wiring in the vehicle. The Honda ECU does not store temporary DTCs so only stored DTCs are shown. Fault codes are stored once the ignition is switched off. Fault codes may be cleared using the Clear DTCs command.
Readiness Codes
Readiness codes indicate which OBDII tests the ECU supports and the status of those tests. The Honda ECU does not support all tests, so 'Not Supported' is normal. Readiness codes are reset to 'Not Complete' when the Clear DTCs command is used.