Fitment

GM diesel vehicles with SCR AdBlue emission system including

• Chevrolet Silverado 2500HD 6.6L Duramax diesel (selected SCR versions)
• Chevrolet Silverado 3500HD 6.6L Duramax diesel
• GMC Sierra 2500HD 6.6L Duramax diesel
• GMC Sierra 3500HD 6.6L Duramax diesel
• Chevrolet Express 2500 / 3500 6.6L diesel
• GMC Savana 2500 / 3500 6.6L diesel
• Selected GM heavy duty diesel SCR systems (2011–2016 range applications depending on calibration)

OE reference
12643694
5WK96645G
12665216 (related system reference)
12648665 (possible cross variant depending on calibration)

FAQ

What is this NOx sensor used for

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

Is this inlet or outlet sensor

It is used in SCR system and can function as either inlet or outlet depending on exhaust layout

Are all 12643694 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