Set Condition
WARNING: This page is about a different variant/trim than selected.
The PCM uses the (upstream) NOx Sensor 1/1 and the (downstream) NOx Sensor 1/2 feedback to calculate the NOx efficiency. The PCM also factors in engine operating and environmental conditions to calculate the DEF dosing rate. The PCM sets this DTC if the NOx Conversion Efficiency is below a calculated threshold target. The PCM will turn on the Malfunction Indicator Lamp (MIL) immediately after the monitor runs and fails.