Mercedes-Benz A 220 2021–2023 — technical service bulletin

Bulletin LI27.19-P-080823 · NHTSA communication 11036514 · issued Aug 25, 2026

Technical service bulletin

communication type

Power Train

component

2021–2023

model years

vehicle entries

Official summary

Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts into N • Concern disappears after ignition cycle When performing a quick test, the following fault code is stored in Y3/14 ‑ Transmission control for 8‑speed dual‑clutch transmission (DKG): P056300 The on‑board power supply voltage is too high. Cause An overvoltage condition is detected exclusively within the transmission control unit, storing fault P056300 once the measured voltage exceeds 16V. Remedy This LI applies if the freeze frame data for P056300 sho

Vehicles covered

What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.