FITMENT:
Compatible with BMW diesel vehicles equipped with SCR (AdBlue/DEF) emission systems, including:

• 3 Series (F30 / F31 / E90 diesel variants)
• X3 (F25)
• X5 (E70 / F15 diesel variants)
• X6 (E71 / F16 diesel variants)
• 5 Series / 7 Series (selected diesel SCR configurations)

OEM reference number: 857647101
Common sensor/module pairing: 5WK96699B (Continental NOx sensor module family)

This unit is part of BMW’s SCR emissions system used for monitoring NOx levels before and after catalytic reduction to control AdBlue dosing and emissions compliance.

FUNCTION:

• Measures nitrogen oxide (NOx) levels in exhaust gases
• Sends data to ECU for SCR/AdBlue dosing control
• Ensures Euro 5 / Euro 6 emission compliance
• Helps optimize catalyst efficiency and prevent limp mode

IMPORTANT NOTE (BMW SYSTEM TYPE):
This part number (857647101) is commonly used as a NOx sensor control module assembly, meaning it may include:

• NOx sensor probe
• Integrated control electronics (CAN module)

BMW often uses a two-part NOx system (sensor + control module) depending on engine generation.

INSTALLATION POSITION:

• SCR system inlet or outlet sensor (vehicle dependent)
• Mounted on exhaust system near DPF/SCR catalyst

Typical mounting location: underbody exhaust section with heat shielding.

FAQ:

Q1: Is this inlet or outlet sensor?
A1: It depends on BMW model. 857647101 is used in both upstream and downstream SCR positions depending on engine (N47 / N57 diesel systems).

Q2: What vehicles commonly use it?
A2: BMW F30 3 Series, F25 X3, E70/F15 X5, E71/F16 X6 diesel models with SCR systems.

Q3: What are failure symptoms?
A3: SCR warning light, engine derate, AdBlue faults, incorrect NOx readings, or limp mode.

Q4: Is this a full sensor or module?
A4: Often it is a sensor + control module assembly, not just a probe.

Q5: Does it need programming after replacement?
A5: Yes, BMW NOx modules typically require adaptation/reset using diagnostic tools (ISTA).