FITMENT:
Compatible with Mercedes-Benz diesel vehicles equipped with SCR (AdBlue/DEF) Euro 5 / Euro 6 emission systems, including:

• E-Class W212 / S212 (E200 / E220 / E250 / E300 / E350 CDI variants)
• E-Class Coupe/Convertible C207 / A207
• CLS-Class W218 / X218
• S-Class W222 / V222 (diesel SCR versions)
• GLK X204 (selected diesel SCR models)
• Sprinter W906 / Vito W447 (some shared SCR systems depending on engine setup)

OEM / Cross reference numbers:

• A0009053403
• 0009053403
• 5WK96681C / 5WK96681D (Continental NOx sensor family)

This NOx sensor is used in Mercedes SCR aftertreatment systems to measure nitrogen oxide levels and regulate AdBlue dosing for emissions compliance.

FUNCTION:

• Measures nitrogen oxide (NOx) in exhaust gas stream
• Sends real-time data to ECU via CAN communication
• Controls SCR/AdBlue injection strategy
• Ensures Euro 5 / Euro 6 emissions compliance
• Monitors catalyst efficiency and system health

INSTALLATION POSITION:

• SCR system inlet or outlet sensor (depends on vehicle configuration)
• Mounted on exhaust line near DPF and SCR catalyst

IMPORTANT NOTE:
This sensor belongs to a widely used Mercedes NOx family. Even if part numbers look similar (A0009053403 / 3506 / 3703), they may differ in:

• Calibration software version
• Harness length
• Connector type
  Always match OEM number or VIN before ordering.

FAQ:

Q1: Is this inlet or outlet sensor?
A1: It can be used as inlet or outlet depending on Mercedes SCR configuration.

Q2: What vehicles does it fit?
A2: Mainly W212 E-Class, C207/A207, W218 CLS, W222 S-Class and related diesel SCR models.

Q3: What are failure symptoms?
A3: SCR warning light, engine limp mode, AdBlue system fault, or NOx efficiency codes.

Q4: Are 5WK96681C and 5WK96681D the same?
A4: They are closely related Continental versions used under Mercedes OEM A0009053403.

Q5: Does installation require programming?
A5: Some Mercedes models require SCR reset or ECU adaptation after replacement.