FITMENT:
Compatible with Freightliner medium-duty trucks equipped with Cummins 6.7L diesel engines and SCR (AdBlue/DEF) systems, including:

• Freightliner M2 106 (2010–2015, 6.7L Cummins ISB engines)
• Some MT45 / MT55 chassis applications
• Other Cummins 6.7L SCR-equipped vocational trucks

OEM / Cross reference numbers:

• 2871978
• 2894945 / 2894945RX / 4326873 (related SCR NOx sensor family depending on revision)
• 5WK96674A / 5WK9 6674A (common aftermarket equivalent in some builds)

This NOx sensor is used in the SCR aftertreatment system to monitor nitrogen oxide levels in exhaust gases and control AdBlue dosing for emissions compliance.

FUNCTION:

• Measures NOx concentration in exhaust stream
• Sends data to ECU/ACM via CAN communication
• Controls DEF (AdBlue) injection for SCR efficiency
• Helps maintain EPA emissions compliance and prevent engine derate

INSTALLATION POSITION:

• SCR system inlet or outlet (depends on OEM configuration)
• Typically mounted on exhaust line between DPF and SCR catalyst or downstream of SCR unit

IMPORTANT NOTE:
The Freightliner M2 platform may use different NOx sensor calibrations (inlet vs outlet) depending on engine year and emissions package. Always confirm by OEM part number or VIN before ordering.

FAQ:

Q1: Is this inlet or outlet sensor?
A1: 2871978 can be used in SCR inlet or outlet position depending on Cummins/Freightliner calibration.

Q2: What symptoms indicate failure?
A2: Check engine light, SCR/DEF warning, engine derate, incorrect NOx readings, or limp mode.

Q3: Is it plug-and-play?
A3: Yes, but some vehicles require SCR reset or ECU adaptation after installation.

Q4: Is 2871978 interchangeable with other Cummins sensors?
A4: Yes, it belongs to a common SCR NOx sensor family shared with multiple Cummins/Freightliner applications, but exact match is required.

Q5: What engine uses it most?
A5: Cummins ISB 6.7L EPA10/EPA13 engines in Freightliner M2 106 trucks.