DESCRIPTION:Selective Catalyst Reduction (SCR) Inlet NOx Sensor – Drift (Low Box).

MONITORED PARAMETER:Engine out NOx.

TYPICAL ENABLING CONDITIONS:1. Exhaust Gas Recirculation (EGR) mass flow greater than .08 kg/s.2. Engine speed is between 1450-1900 RPM.3. Engine torque is between 1400-2100 N·m (1033 to 1549 lb·ft).4. Battery voltage greater than 11 vDC.5. Coolant temperature greater than 65°C (149°F).6. Ambient temperature greater than -8°C (17.6°F) ambient.7. Barometric pressure greater than 755 mbar.8. Engine is not in regeneration mode.

MONITOR SEQUENCE:None

EXECUTION FREQUENCY:Always enabled

TYPICAL DURATION:1.2 seconds

DASH LAMPS:MIL

ENGINE REACTION:None

VERIFICATION:1. Warm up engine such that coolant temperature greater than 65°C (149°F).2. Ensure engine is not in regeneration mode.3. Ensure ambient temperature greater than -8°C (18°F) barometric pressure greater than 755 mbar.

NOTE: If any other EGR codes are active, fix those first.

PROBABLE CAUSES:1. Inspect the entire air inlet system, charge air cooler, and EGR piping/hoses.2. Check for failed injector.3. Check the aftertreatment system for leaks/damage.4. Perform a high idle regeneration