John Deere 3216.12 – Engine Control Unit (ECU): Aftertreatment Inlet NOx Sensor Faulty

The NOx sensor located at the inlet of the exhaust aftertreatment system detects a problem with its own measurement capabilities, reporting an inability to accurately measure nitrogen oxide (NOx) levels in the exhaust gases before they pass through the DPF and SCR systems.

• 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
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 7R Series
• 6105M
• 310E Backhoe Loader
• Vermeer D24x40 S3
• Vermeer D40x55 S3

1. 1

   Inspect the Inlet NOx sensor for physical damage, heavy soot/contamination, or signs of extreme heat.

2. 2

   Check the sensor's wiring harness and connectors for physical damage, corrosion, or loose pins that could affect its performance.

3. 3

   Ensure there are no active CAN Bus communication codes (such as 003216.09). If communication codes are present, the issue is likely in the wiring harness rather than the sensor itself.

4. 4

   Utilize a John Deere diagnostic scan tool (Service ADVISOR) to assess the sensor's output and responsiveness to verify it is functioning outside of specified parameters.

1. 1

   Turn off the machine and allow the exhaust system to cool completely to avoid severe burns.

2. 2

   Locate the Aftertreatment Inlet NOx Sensor (positioned upstream of the DPF/SCR assembly).

3. 3

   Disconnect the electrical connector for the sensor.

4. 4

   Carefully unthread and remove the faulty sensor from the exhaust pipe.

   Penetrating oil may be required if the threads are seized.

5. 5

   Install the new Inlet NOx sensor and tighten it to the manufacturer's specified torque.

6. 6

   Reconnect the electrical harness securely.

7. 7

   Connect a diagnostic tool to clear the 003216.12 fault code from the ECU and reset the aftertreatment system parameters.

8. 8

   Perform a system check or test run to ensure the emission levels are within regulatory requirements and the code does not return.