In the app: Faults→Scan all modules
From the guide: Fault codes
State: active (the fault is present now), pending, stored (happened before), warning lamp (the module asked for a warning light).
From the guide: Faults tab
Scan all modules reads stored fault codes from 39 modules (about a minute). Codes are marked Active now, Pending, Stored or Warning lamp; tap Active now to list active codes first. New marks codes that weren't there in the last scan; Cleared since last scan lists codes that went away. Some lists may be incomplete; scanning again usually fills them in.