John Deere Engines SPN3711FMI31 Fault Code: DOC Inlet Temperature Target Not Reached During ETM

What does John Deere Engines error code SPN3711FMI31 mean?

SPN 3711 FMI 31 is a John Deere engine diagnostic trouble code tied to the exhaust aftertreatment system. The DOC, or diesel oxidation catalyst, needs to reach a certain inlet temperature during an engine temperature management (ETM) event so that active regeneration of the diesel particulate filter can burn off accumulated soot. When the ECU sees that this temperature target was not reached while a regeneration was actively running, it logs this code.

The alarm level for this code is a Warning. That means the engine keeps operating, but the ECU is telling the operator and the shop that regeneration is not completing the way it should because exhaust gas temperature is coming in low.

The direct consequence listed is that diesel particulate filter active regeneration gets inhibited due to low exhaust gas temperature, while the ECU tries to maintain proper operating conditions in the background. Left unaddressed, this can lead to reduced regeneration effectiveness over time.

What triggers a John Deere Engines SPN3711FMI31 code?

The code sets when the engine is running, a regeneration is in progress, and the ECU detects that the DOC inlet temperature target was not reached during ETM. No specific voltage, pressure, or numeric temperature threshold is given for this set condition.

Common causes of SPN3711FMI31

• Exhaust system leaks (leaking or leaks in the exhaust system), which let hot exhaust gas escape before it reaches the DOC, dropping the inlet temperature seen by the ECU below what is needed for regeneration.
• A bad air throttle actuator (also referred to in some versions as a bad exhaust throttle), which fails to properly restrict airflow to help build and hold exhaust temperature during a regeneration event.
• Other related fault codes present at the same time. Deere's troubleshooting sequence for this code lists a long set of related SPNs to check first, including SPN 27, SPN 51, SPN 2795, SPN 3246, SPN 3465, SPN 3471, SPN 3480, SPN 3482, SPN 3510, SPN 3511, SPN 3514, SPN 3556, SPN 4077, SPN 4360, SPN 4765, SPN 4766, SPN 5126, SPN 5127, SPN 5298, SPN 5456, and SPN 5743. Any active DTC on these SPNs should be resolved before chasing SPN 3711 FMI 31 on its own.

How to troubleshoot John Deere Engines SPN3711FMI31: first checks

1. 1)Pull up the full active and stored fault code list first. Because this code's own troubleshooting sequence calls out a large group of related SPNs, check whether any of those are also active. Fixing those first often resolves this code as a side effect.
2. 2Inspect the exhaust system for leaks between the turbocharger outlet and the DOC inlet, including gaskets, clamps, flex sections, and welds. A leak here bleeds off exhaust heat before it reaches the aftertreatment system.
3. 3Inspect and test the air throttle actuator (or exhaust throttle, depending on the engine configuration) for proper operation. A stuck, sluggish, or miscalibrated throttle actuator can prevent the engine from building the exhaust temperature needed for regeneration.
4. 4Confirm the regeneration event was actually running when the code set, and check machine hour/service records for any pattern of incomplete regenerations, since a habit of interrupted regens points toward the same root cause repeating.

How the code clears

No separate clearing step or reset procedure is listed for this code. Since the alarm level is a Warning tied to a specific regeneration event, correcting the exhaust leak or actuator problem and allowing a normal regeneration cycle to complete is the expected path to clearing it. Always verify with a diagnostic tool that the code is no longer active after repairs.