SSM 54291

Some 2026 Transit vehicles built with the Delivery Assist feature (minor feature code AAEAZ) may exhibit diagnostic trouble code (DTC) U2013:04 stored in the accessory protocol interface module (APIM) when a diagnostic self-test is performed. To confirm a vehicle is built with minor feature code AAEAZ, review the build information by double-clicking the vehicle identification number (VIN) in the upper left corner of the Professional Technician System (PTS). If there are no observable symptoms with the audio controls, no further action is required. Replacement and/or programing of the APIM or audio controls will not resolve this condition. If there is an observable symptom, follow normal Workshop Manual diagnostics.