NOX SENSOR 5WK9 6682D A0009053503 For MERCEDES W205 C220 ML350 W166

Restore correct AdBlue dosing and emission control on modern diesels on your Mercedes-Benz W205 C220 Ml350 W166 with this direct-replacement nox sensor — also known as the nitrogen oxide sensor, exhaust NOx probe or SCR sensor. Built to OEM specification and matching part numbers A0009053503, 000-905-35-03, 6682D, 0065427218 and A0065427218.

Common signs of failure

A failing NOx sensor on diesel vehicles typically triggers fault codes P220A, P220B, P220C, P229F or P207F (NOx sensor circuit / SCR system efficiency). Drivers see the engine warning light come on, an AdBlue or 'Emissions' warning on the dashboard, often a countdown 'Vehicle will not start in X miles' message, and in many cases the vehicle entering limp mode. Left unaddressed, the ECU will eventually prevent the engine from restarting until the fault is cleared.

Fitment notes

Direct-fit replacement, with the original wiring harness and ECU connector. After fitting, the sensor needs a short re-learn drive cycle (typically 5–20 minutes of motorway driving) for the ECU to calibrate to the new probe. Some manufacturers recommend resetting adaptations with a diagnostic tool — useful but not strictly required on most models. Standard 5 pin connector. Position: Front Or Rear.

Frequently asked questions

Where is the NOx sensor located?

Most diesel vehicles have two NOx sensors: one upstream and one downstream of the SCR catalyst/AdBlue injection point. Identify whether your fault is for the inlet or outlet sensor (the code and live data will tell you) before ordering.

Will it fix my limp-mode and AdBlue warning?

Yes, if the fault code points to the NOx sensor itself. After fitting, clear the codes and complete a regen drive cycle — warnings usually clear within a few miles.

How long do NOx sensors last?

Typically 80,000–120,000 miles, though heavy stop-start driving and poor-quality AdBlue can shorten lifespan. Replacement at the first sign of failure prevents the vehicle locking you out.