John Deere Engines SPN3514FMI3 Fault Code: Sensor Supply #6 Voltage Out of Range High
Also called Engine Shutdown Commanded by Application
Sensor Supply #6 Voltage Out of Range High · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 3514 FMI 3 sets when the John Deere engine ECU sees Sensor Supply #6 voltage go above 5.26 V. This 5-volt supply feeds several sensors depending on engine configuration, including the DPF differential pressure sensor, engine coolant pressure sensor, exhaust filter temperature module, fuel dosing pressure sensors, exhaust manifold pressure sensor, and the EGR valve. The alarm level is listed as Warning, and the ECU tries to maintain proper operating conditions while the fault is active.
Medium severity. The code is logged as a Warning level alarm, not a shutdown-level fault, but it affects a shared 5-volt supply that multiple emissions and cooling sensors depend on. Left unaddressed, it can cause inaccurate readings from any sensor on that circuit, which can affect DPF regeneration, EGR control, or coolant pressure monitoring. Diagnose it within the shift rather than ignoring it.
What does John Deere Engines error code SPN3514FMI3 mean?
SPN 3514 FMI 3 is a John Deere engine ECU code meaning the ECU has detected a supply voltage above specification on its 5-volt Sensor Supply #6 circuit. Specifically, the ECU sees voltage greater than 5.26 volts on this circuit when it should be regulated at a lower, steady level.
This supply circuit is shared by several sensors depending on the exact engine and emissions configuration. Depending on the model, Sensor Supply #6 can feed the Exhaust Filter Temperature Module, DPF Differential Pressure Sensor, Engine Coolant Pressure Sensor, Fuel Dosing Outlet Pressure Sensor, Fuel Dosing Inlet Sensor, Exhaust Manifold Pressure Sensor, and the EGR Valve. Because one supply line feeds multiple sensors, a single wiring or connector problem can throw off readings across several systems at once.
One of the descriptions tied to this code is listed as 'Engine Shutdown Commanded by Application,' though the alarm level itself is recorded as a Warning. The ECU's control unit response is simply to try to maintain proper operating conditions while the high supply voltage condition exists.
What triggers a John Deere Engines SPN3514FMI3 code?
The ECU sets this code when the ignition is on and it detects supply voltage greater than 5.26 volts on the Sensor Supply #6 circuit.
Common causes of SPN3514FMI3
- Bad Exhaust Filter Temperature Module, DPF Differential Pressure Sensor, Engine Coolant Pressure Sensor, Fuel Dosing Outlet Pressure Sensor, or Fuel Dosing Inlet Sensor
- Bad Exhaust Manifold Pressure Sensor, Engine Coolant Pressure Sensor, or EGR Valve (on engines where those are the sensors fed by this supply)
- Short in the harness, including a short to voltage on the supply wire or on a signal wire
- Open in the harness
- Mispin in the harness
- Bad terminals or connector at the ECU
- Bad terminals or connector at the affected sensor or module
- Bad ECU
- Outdated or bad ECU software
How to troubleshoot John Deere Engines SPN3514FMI3: first checks
- Confirm the DTC is active with the ignition on, since that is when this fault is displayed, and note whether other related codes such as SPN 5127 FMI 3 are also active, since some troubleshooting sequences run that code first
- Identify which sensors your engine configuration uses on Sensor Supply #6 (this varies: some engines use the DPF/exhaust filter/fuel dosing sensors, others use the exhaust manifold pressure sensor, coolant pressure sensor, and EGR valve) so you know which components to inspect
- Inspect connectors and terminals at the ECU and at each sensor fed by Sensor Supply #6 for corrosion, looseness, or damage
- Check the wiring harness for an open circuit, a short to voltage, or a mispinned connector on the supply and signal wires
- Measure the Sensor Supply #6 voltage directly at the ECU and at each sensor connector to see if it reads above 5.26 volts, and compare readings to isolate whether the problem is in the harness, a sensor, or the ECU itself
- If wiring and sensors check out, consider whether ECU software is outdated, and verify ECU health before replacing it
How the code clears
No separate clearing step is listed. Once the wiring, connector, sensor, or ECU issue causing the high Sensor Supply #6 voltage is repaired, the code should stop being active on the next key cycle. Always verify the fix by cycling the ignition and confirming the fault does not reset.
Frequently asked questions
What does SPN 3514 FMI 3 mean on a John Deere engine?
It means the ECU detected voltage above 5.26 volts on its Sensor Supply #6 circuit, a 5-volt supply that feeds one or more sensors depending on your engine's configuration, such as the DPF differential pressure sensor, engine coolant pressure sensor, EGR valve, or fuel dosing pressure sensors.
Is SPN 3514 FMI 3 a serious fault?
It is logged at a Warning alarm level, so it is not an immediate shutdown code, but because it affects a shared sensor supply circuit it can cause inaccurate readings on multiple sensors. It is best treated as a diagnose-soon issue rather than something to ignore.
Which sensors are affected by SPN 3514 FMI 3?
Depending on the engine configuration, Sensor Supply #6 can feed the Exhaust Filter Temperature Module, DPF Differential Pressure Sensor, Engine Coolant Pressure Sensor, Fuel Dosing Outlet Pressure Sensor, Fuel Dosing Inlet Sensor, Exhaust Manifold Pressure Sensor, and the EGR Valve. Check which of these your specific engine uses.
What causes the Sensor Supply #6 voltage to go too high?
Common causes include a bad sensor on that circuit, a short to voltage in the harness (on either the supply or a signal wire), an open circuit, a mispinned connector, corroded or damaged terminals at the ECU or sensor connectors, a bad ECU, or outdated ECU software.
Will SPN 3514 FMI 3 cause an engine shutdown?
One of the descriptions associated with this code references 'Engine Shutdown Commanded by Application,' but the alarm level for this specific fault is recorded as a Warning, and the ECU's response is to try to maintain proper operating conditions rather than force an immediate shutdown.
How do I fix SPN 3514 FMI 3?
Inspect and repair connectors and terminals at the ECU and at the affected sensors, check the harness for shorts, opens, or mispins, verify supply voltage readings, and confirm ECU software is current. Replace the faulty sensor or ECU only after wiring and connections have been ruled out.
Does this code always point to the same sensor?
No. Because Sensor Supply #6 wiring varies by engine build, it can be tied to the DPF and fuel dosing sensors on some engines and to the exhaust manifold pressure sensor, coolant pressure sensor, and EGR valve on others. Always confirm which sensors your specific engine has wired to that supply before troubleshooting.