S2118000004

Case Number: S2118000004
Release Date: April 2021
Symptom/Vehicle Issue: Malfunction Indicator Lamp (MIL) Illumination. Diagnostic
Trouble Codes (DTCs) P225D – NOX Sensor 1/1 Performance, Signal Stuck Low
And/Or P225C – NOX Sensor 1/1 Performance, Signal Stuck High, Set.
NOTE: Please ensure the PCM is at the latest available calibration before
proceeding. Refer to all applicable published TSBs for current flash procedures.
NOTE: Be sure to diagnose and repair any additional PCM DTCs first before
diagnosing P225C, or P225D.
Discussion: Some customers may experience a MIL illumination. Upon further
investigation, a technician may find DTC P225D and/or P225C set in the Powertrain
Control Module (PCM).
An analysis of returned NOx sensors that were replaced for these DTCs has revealed
that the majority of these sensors are Trouble Not Found (TNF). Further research has
revealed that there are several other different possible causes that can lead to these
DTCs. The other possible cases are:
 Intake System Leaks – Including leaks in the Charge Air Cooler (CAC) system.
 EGR System Leaks – Including, but not limited to, an LP EGR valve that is
partially stuck open.
 Fuel System Issues – Including fuel contamination that could lead to the sensor
ports becoming clogged with soot.
 Skewed MAF Sensor Inputs
 Skewed Engine Coolant Temp Sensor Inputs
This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online
does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear
to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the
appropriate course of action.
Contact STAR Center, or your Technical Assistance Center Via TechCONNECT or eCONTACT ticket if no
solution is found
FCA US LLC
Version 4.3 10/29/2020
The current diagnostic flow charts for these DTCs are currently being revised to add
these additional possible causes into the diagnostic steps. When diagnosing a vehicle
with the above DTCs, please inspect/test for these additional areas, and repair as
necessary. If diagnosis reveals no trouble found, engineering is currently investigating
the issue for a possible future software update.
This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online
does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear
to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the
appropriate course of action.
Contact STAR Center, or your Technical Assistance Center Via TechCONNECT or eCONTACT ticket if no
solution is found
FCA US LLC
Version 4.3 10/29/2020