Fitment

GM diesel vehicles with SCR AdBlue Euro 5 Euro 6 emission system including

• Chevrolet Silverado 2500HD 6.6L Duramax diesel (2011–2013 LML platform)
• Chevrolet Silverado 3500HD 6.6L Duramax diesel
• GMC Sierra 2500HD 6.6L Duramax diesel
• GMC Sierra 3500HD 6.6L Duramax diesel
• Selected GM heavy-duty diesel SCR systems (LML platform)

OE reference
12638378
5WK96645B
12665216 (related variant reference)
12671387 (alternate OE cross reference)

FAQ

What is this NOx sensor used for

It measures nitrogen oxide levels in diesel exhaust gas and sends data to ECU for SCR AdBlue emission control system

Is this inlet or outlet sensor

It is used in SCR system and may function as inlet or outlet depending on exhaust configuration

Are all 12638378 sensors interchangeable

No GM NOx sensors are ECU coded and must match exact OE number and calibration version

What system does it work with

SCR Selective Catalytic Reduction system using AdBlue injection for diesel emission compliance

What are common failure symptoms

Engine warning light SCR AdBlue fault reduced power limp mode NOx sensor communication error emission efficiency faults