John Deere 3226.14 – ECU: Aftertreatment Outlet NOx Sensor Faulty / Data Invalid

The aftertreatment outlet NOx sensor has detected a problem with its measurement. It is unable to accurately measure the nitrogen oxides (NOx) levels in the exhaust after the gases have passed through the Selective Catalytic Reduction (SCR) emission control system. This compromises the machine's ability to monitor SCR efficiency and meet emissions standards.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 9470RT
• 9520RT
• 9570RT
• 8245R to 8400R
• 6105M
• 5075GV
• 5090GV
• 444K
• 544K
• 644K
• 724K
• 824K
• 130G
• 180GLC
• 210GLC
• R4023

1. 1

   Inspect the outlet NOx sensor for physical damage, heavy soot accumulation, or contamination that might interfere with its function

2. 2

   Check the wiring harness and connector for the NOx sensor. Verify that the CAN bus termination resistance is correct (typically 60 ohms across the circuit) and check for proper CAN Hi/Low voltages

3. 3

   Use a diagnostic tool (such as John Deere Service ADVISOR) to assess the accuracy of the sensor's output against expected NOx concentrations under similar operating conditions

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts or ECU damage.

2. 2

   Locate the Sensor

   Locate the Aftertreatment Outlet NOx Sensor, which is mounted on the exhaust pipe at the outlet of the SCR/DPF aftertreatment system.

3. 3

   Disconnect

   Unplug the electrical connector linking the NOx sensor module to the machine's wiring harness.

4. 4

   Remove the Sensor

   Carefully unscrew the sensor probe from the exhaust pipe (penetrating oil may be required if the threads are seized).

5. 5

   Install the New Sensor

   Thread the new NOx sensor into the exhaust pipe and tighten to OEM torque specifications. Note: The sensor probe and its control module box are permanently attached and must be serviced/replaced as a single component.

6. 6

   Reconnect

   Plug the electrical connector back into the harness.

7. 7

   Clear Codes & Reset

   Reconnect the battery. Use a diagnostic tool to clear the 003226.14 fault code and reset the ECU.

8. 8

   Verify Repair

   Conduct an "SCR Performance and System Test" or run the machine under load to ensure the new sensor provides accurate readings and the code does not return.