Mercedes-Benz check engine codes
Overview
Mercedes-Benz engines commonly set lean codes from vacuum leaks and aging sensors, and catalyst codes at higher mileage.
Codes notably common on Mercedes-Benz
We have not found well documented brand patterns for our 20 codes on this make. Every code works the same way here as on other vehicles.
Mercedes-Benz specific notes
- We have not found well documented Mercedes-Benz patterns specific to these codes. Lean codes follow the general causes: vacuum leaks and the MAF sensor.
Owner's manuals
Official Mercedes-Benz owner's manual / owner portal (manufacturer site; we do not host copies).
Repair manuals
Step-by-step service manuals for Mercedes-Benz with torque specs and wiring diagrams:
Haynes manuals for Mercedes-Benz Chilton manuals
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Recall lookup
Check open Mercedes-Benz recalls with your VIN at the NHTSA recall lookup.
Sources
Sources checked October 2026. Bulletins apply only to the models and years they list.
All other codes
These work the same on Mercedes-Benz as on any vehicle:
P0420 P0430 P0300 P0301 P0302 P0303 P0304 P0171 P0174 P0440 P0442 P0455 P0456 P0128 P0135 P0141 P0101 P0299 P2135 P0401