Theory Of Operation
WARNING: This page is about a different car, the 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The engine aftertreatment system monitors the oxygen content in the diesel engine exhaust. The Powertrain Control Module (PCM) monitors the exhaust gases for oxygen content and varies the rich/lean fuel mixture of the intake air fuel mixture to adjust system. This diagnostic measures the oxygen storage capability of the Nitrates of Oxygen (NOx) Absorber Catalyst. The PCM will set the fault if it detects that the NOx Absorber performance is lower than expected. A mobile desoot should not be performed while investigating this fault. The PCM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The PCM will turn off the MIL lamp diagnostic runs and passes in four consecutive drive cycles.