C4.4 Engines Clean Emissions Module Has High Oxygen Level Caterpillar

Clean Emissions Module Has High Oxygen Level

C4.4 Engines [UENR0662]

C4.4 Engines Acceleration Is Poor or Throttle Response Is Poor

C4.4 Engines DEF Pressure Is High

AIR INLET AND EXHAUST SYSTEM

AFTERTREATMENT GP

C4.4 Engines Diesel Oxidation Catalyst Has Low Conversion Efficiency

C4.4 Engines Clean Emissions Module Has High Oxygen Level

C4.4 Engines DEF Pressure Is High

C4.4 Engines Codes that Inhibit Operation of Aftertreatment System

C4.4 Engines DEF Tank Temperature Is High

C4.4 Engines DEF Tank Temperature Is Low

C4.4 Engines Diesel Oxidation Catalyst Has Incorrect Inlet Temperature

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Table 1
Diagnostic Trouble Codes
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
3217-16	E1407 (2)	Aftertreatment #1 Intake O2 : High - moderate severity (2)	The Engine Out NOx Sensor is reading a higher than expected level of Oxygen (O2).
3227-16	E1408 (2)	Aftertreatment #1 Outlet O2 : High - moderate severity (2)	The Tailpipe Out NOx Sensor is reading a higher than expected level of Oxygen (O2).
Follow the troubleshooting procedure to identify the root cause of the problem.

Diesel Oxidation Catalyst (DOC)/Selective Catalytic Reduction (SCR) Aftertreatment

The SCR intake NOx sensor is located in the exhaust pipe between the Exhaust Back Pressure Regulator (EBPR) and the DOC inlet. The SCR outlet NOx sensor is located in the exhaust tail pipe.

DOC/Diesel Particulate Filter (DPF)/SCR Aftertreatment

The SCR intake NOx sensor is located in the Clean Emissions Module (CEM) after the DPF. The SCR outlet NOx sensor is located in the exhaust tail pipe.

The exhaust system has two NOx sensors that measure O2 and NOx. The inlet sensor monitors the NOx and O2 entering the SCR catalyst. The outlet sensor monitors the NOx and O2 exiting the SCR catalyst.

Complete the procedure in the order in which the steps are listed.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check if NOx Sensors are Installed A. Locate the appropriate NOx Sensor. B. Check if the sensor is installed correctly.	Correctly Installed / Not installed correctly	Result: The sensor is not installed correctly. Repair: Install the sensor correctly. Proceed to Test Step 3. Result: The sensor is installed correctly. Proceed to Test Step 2.
2. Check for an Exhaust Leak Between the Turbocharger and the Tailpipe A. Check for disconnected exhaust pipes. B. Check for broken/loose joints.	Leak found	Result: An exhaust leak is found between the turbo and the tail pipe. Repair: Repair the exhaust leak. Proceed to Test Step 3.
3. Perform the Aftertreatment System Functional Test A. Reset all active codes and clear all logged codes. B. Use the electronic service tool to perform the "Aftertreatment System Functional Test" to verify that the fault is eliminated.	Test passed	Result: The "Aftertreatment System Functional Test" passed. The NOx sensing system is fully functional and the fault has been eliminated. Return the unit to service. Result: The "Aftertreatment System Functional Test" did not pass and the diagnostic code is still present. Repair: Ensure that the latest engine software is installed. Refer to Troubleshooting, ECM Software - Install for the correct procedure. Replace the sensor. If the fault is still present, contact the Dealer Solutions Network (DSN).