Mercedes-Benz A 220 2013–2025 — technical service bulletin

Bulletin LI01.20-P-078446 · NHTSA communication 11008712 · issued Oct 4, 2024

Technical service bulletin

communication type

Engine

component

2013–2025

model years

vehicle entries

Official summary

Complaint Check engine light on. One of the below fault codes is current in the engine control module (N3/10). P04DB29, P04DB31, P04DB79 Cause Open circuit or high resistance to crankcase vent line contact Remedy 1. Check the electrical connector for the relevant vent line contact switch noted below. Refer to attached photos of connection locations. 2. Ensure the bolted connection is secure and bolt can be torqued (9Nm). 3. Check continuity from vent line connection to ME control unit. Repair wire if damage is found. • The circuit from ME provides 5V and is pulled to 0V when the ground connect

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.