DESCRIPTION:
Outlet NOx sensor drifted high.

MONITORED PARAMETER:
Selective catalyst reduction (SCR) outlet NOx.

TYPICAL ENABLING CONDITIONS:
Always enabled

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Two seconds

DASH LAMPS:
MIL

ENGINE REACTION:
None

VERIFICATION:
Parked regeneration

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

PROBABLE CAUSES:
1. Check the aftertreatment system for leaks/damage.
2. Perform a high idle regeneration with the metering valve or dosing unit disconnected.