DTC B278D Id Code Box Recognition Judgment Abnormal: DTC Detecting Condition

WARNING: This page is about a different car, the 2015 Subaru XV Crosstrek and 2015 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

When ID code box setting is set to OFF, ID code box ON input is detected.
When ID code box setting is set to OFF, ID code box LIN signal is received.