John Deere Engines SPN100FMI1 Fault Code: Engine Oil Pressure Signal Extremely Low
Also called Engine Oil Pressure Extremely Low
Engine Oil Pressure Signal Extremely Low · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 100 FMI 1 (also shown as DTC 000100.01) means the ECU has detected engine oil pressure below the shutdown set point, or on switch-equipped engines, that the oil pressure switch is open after the engine has run above cranking RPM for several seconds. This is a serious engine protection fault that will derate power and can shut the engine down. Stop and check oil pressure immediately.
Critical severity. This code triggers engine protection. Depending on how the ECU is programmed, the engine will derate power (rates vary by application, including 20%, 40%, or 60% per minute figures reported across different programming) and may shut down completely, commonly 30 seconds after the code sets. Treat this as a stop-now condition, not a drive-it-in problem.
What does John Deere Engines error code SPN100FMI1 mean?
SPN 100 FMI 1 is set by the engine ECU when it sees oil pressure that is dangerously low, either through a pressure sensor or, on some applications, an oil pressure switch. The oil pressure sensor is a pressure transducer plumbed into the main oil gallery (or oil cooler on some engines). As oil pressure rises, the sensor's output voltage rises too, so the ECU can track pressure in real time and compare it to a shutdown threshold that changes with engine speed.
On engines that use a switch instead of a sensor, the switch's contacts close when there is enough oil pressure and open when pressure drops below the minimum threshold. The switch is always open with the engine off, so the ECU only evaluates it once the engine has been running above cranking RPM for a few seconds.
Because this fault protects the engine from running with insufficient lubrication, the ECU response is aggressive. Depending on how the OEM configured the ECU, you may see a straight derate, a derate followed by shutdown, or in rare cases (protection disabled) no action at all. On many applications SPN 1569 FMI 31 will also be present, and on shutdown-enabled units, codes 001109.31 and 001110.31 can also appear alongside this fault.
What triggers a John Deere Engines SPN100FMI1 code?
For engines with an oil pressure sensor, the ECU sets this code when it senses oil pressure below the shutdown value set point, which depends on engine speed. One documented threshold is oil pressure below 41 kPa (0.41 bar / 6.0 psi) at an engine speed above low idle. For engines with an oil pressure switch, the code sets when the ECU sees the switch open after the engine has been running above cranking RPM for several seconds.
Common causes of SPN100FMI1
- Bad oil pressure sensor wiring, including opens or shorts in the harness
- Bad or failed oil pressure sensor
- Bad terminals or connector at the oil pressure sensor
- Bad terminals or connector at the ECU
- Defective engine housing, sensor bore, or sensor O-ring allowing a false low reading
- Bad ECU or bad ECU software
- An actual engine issue causing genuinely low oil pressure (worn bearings, oil pump problems, low oil level, wrong oil, blocked pickup, etc.)
How to troubleshoot John Deere Engines SPN100FMI1: first checks
- Before anything else, check the engine oil level and condition. Low oil, badly diluted oil, or the wrong viscosity can cause a real low pressure condition that has nothing to do with the sensor or wiring.
- Without disconnecting anything, visually inspect the ECU connectors and the oil pressure sensor connector for corrosion, contamination, damage, or a connector that is not fully seated. Inspect the wiring harness between the sensor and ECU for chafing, pinches, or damage.
- If the application uses an oil pressure switch (a 2-wire device) instead of a sensor (a 3-wire device), confirm which one you have, since the troubleshooting path is different for each.
- Under the conditions where the code is active, measure actual engine oil pressure with a mechanical gauge to confirm whether the pressure is truly low or the sensor/switch is giving a false signal.
- Use a proper connector adapter test kit (John Deere lists JT07328) to probe connector terminals. Do not force probes directly into connector terminals, this damages the terminals and can create a new fault.
- Check for other codes that may confirm engine protection is active, such as SPN 1569 FMI 31, or 001109.31 / 001110.31 on shutdown-enabled applications.
How the code clears
No separate clearing step is listed beyond fixing the root cause. Once actual oil pressure is restored above the shutdown/threshold value and the wiring, sensor, or switch fault is corrected, the code should stop being active on the next key cycle or engine run. If the ECU shut the engine down, correct the oil pressure problem before attempting to restart.
Frequently asked questions
What does SPN 100 FMI 1 mean on a John Deere engine?
It means the ECU has detected extremely low engine oil pressure, either directly from an oil pressure sensor reading below the shutdown set point, or from an oil pressure switch that is open after the engine has run above cranking RPM for a few seconds. It is an engine protection fault, not a minor warning.
Will my engine shut down if this code sets?
It depends on how the ECU was programmed by the OEM. If the shutdown feature is enabled, the engine will derate and then shut down, commonly 30 seconds after the code sets. If only the derate feature without shutdown is enabled, the engine will lose power (derate rates of 20%, 40%, or 60% per minute appear depending on the application) down to a minimum power level but keep running. Some configurations have no engine protection at all and will not derate or shut down.
Is this code caused by low oil or by a bad sensor?
It can be either. Genuinely low oil pressure from low oil level, worn engine components, or oil pump trouble will trigger this code, but so will a bad oil pressure sensor, a bad oil pressure switch, corroded connectors, or wiring damage. Always confirm actual oil pressure with a mechanical gauge before replacing parts.
What is the difference between the oil pressure sensor and the oil pressure switch on these engines?
The sensor is a 3-wire pressure transducer that sends a variable voltage signal that rises with oil pressure, letting the ECU track pressure continuously. The switch is a 2-wire device that simply opens or closes contacts at a set pressure threshold, giving the ECU an on/off signal instead of a continuous reading. Which one your engine has depends on the application.
Can I keep driving or working with this code active?
No. This code indicates the ECU believes oil pressure is dangerously low, and engine protection derate or shutdown will already be in progress. Stop the engine as soon as it is safe to do so and check oil level and pressure before continuing operation.
What other codes might show up with SPN 100 FMI 1?
SPN 1569 FMI 31 commonly sets alongside this code to indicate the derate condition. On shutdown-enabled applications, codes 001109.31 and 001110.31 can also appear, with 001109.31 typically setting about 30 seconds before the ECU shuts the engine down.
Do I need special tools to check the wiring?
John Deere recommends using a connector adapter test kit (JT07328) to take measurements at the connectors instead of forcing test probes into the terminals directly, since forcing probes into terminals can damage them and create additional problems.