John Deere Engines SPN974FMI4 Fault Code: Remote Analog Throttle Signal Out of Range Low
Remote Analog Throttle Signal Out of Range Low · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 974 FMI 4 means the ECU sees a remote analog throttle signal voltage that is lower than the throttle's physical low-voltage specification. The engine forces throttle to 0% until the signal is valid again, and depending on the configured recovery mode it may need a manual return to idle or a power cycle before normal throttle response comes back.
Medium severity. This code is logged as a Warning level alarm, not a shutdown code. However, it forces throttle command to 0%, which can stop machine operation or PTO-driven work until the fault clears and, depending on the recovery mode configured, until the operator or a technician takes further action. Treat it as a stop-and-diagnose issue rather than an emergency, but do not ignore it since it can leave equipment stuck at idle in the field.
What does John Deere Engines error code SPN974FMI4 mean?
SPN 974 FMI 4 fires when the ECU reads a voltage on the remote analog throttle signal circuit that is below what the throttle could physically ever produce. In other words, the ECU knows the signal cannot possibly represent a real throttle position, and it is being told to distrust the input and default to zero throttle.
This is strictly an electrical signal-range fault. It does not evaluate whether the operator is actually pressing the throttle correctly, it only checks whether the voltage on the circuit falls within a range that is physically possible for the sensor.
The code is displayed whenever the ignition is on and the fault condition is active. On OEM installations, the remote analog throttle is set up in the ECU on the Trim page, and incorrect trim configuration can itself trigger this code even if the wiring and sensor are fine.
Common causes of SPN974FMI4
- Bad terminals or connector at the remote analog throttle connector
- Bad terminals or connector at the ECU connector
- Open or high resistance in the return or supply wires between the throttle and ECU
- Open or shorted harness, including at the X5020 connector where applicable
- Bad or mispinned wiring harness
- Bad remote analog throttle sensor (bad throttle)
- Bad ECU software
- Bad ECU
- Incorrect Trim page configuration for the remote analog throttle in OEM applications
How to troubleshoot John Deere Engines SPN974FMI4: first checks
- Verify ignition is on and confirm the fault is currently active before condemning any parts, since this code only displays under that condition.
- Inspect the remote analog throttle connector and terminals for corrosion, looseness, bent pins, or moisture intrusion.
- Check the ECU connector and terminals for the same issues: corrosion, loose pins, poor seating.
- Inspect the X5020 connector, where equipped, for damage or poor connection.
- Trace the harness between the throttle and ECU for chafing, pinches, or open/shorted wiring in the supply and return legs.
- On OEM installations, confirm the remote analog throttle Trim page settings in the ECU are configured correctly, since misconfiguration alone can set this code.
- If wiring, connectors, and Trim configuration all check out, suspect the throttle sensor itself, then ECU software, then the ECU as later steps.
How the code clears
No separate clearing step beyond restoring a valid signal is listed. Because the ECU forces throttle to 0% once this fault is active, how the machine returns to normal operation depends on which recovery mode is configured: Idle Recovery (the default) requires the operator to return the throttle to slow/low idle (0% throttle) once the signal is valid again before normal control resumes; Resume Recovery restores normal throttle operation automatically as soon as the out-of-range condition clears, which can cause a large jump in engine speed if the fault was intermittent; Locked Recovery requires both a valid signal AND a power cycle of the ECU before normal throttle operation resumes.
Frequently asked questions
What does SPN 974 FMI 4 mean on a John Deere engine?
It means the ECU detected a remote analog throttle signal voltage lower than the throttle's physical low-voltage specification, a value the throttle could never actually produce. The ECU responds by forcing throttle command to 0% until the signal is valid again.
Will my engine shut down when this code sets?
No. This is logged as a Warning level alarm, not a shutdown fault. The practical effect is that throttle is forced to 0%, so the machine may sit at idle or refuse to respond to the throttle until the fault clears and the configured recovery mode allows normal operation to resume.
Why won't my throttle respond even after the fault seems to clear?
This depends on the recovery mode configured in the ECU. Under Idle Recovery, the operator must return the throttle to slow/low idle position before normal control resumes. Under Locked Recovery, the signal must become valid again AND the ECU must be power cycled. Only Resume Recovery restores throttle automatically once the signal is valid, and that mode can cause sudden speed changes if the fault was intermittent.
Is SPN 974 FMI 4 related to SPN 3513?
Yes. The diagnostic troubleshooting sequence groups SPN 3513 FMI 3, SPN 3513 FMI 4, SPN 974 FMI 3, and SPN 974 FMI 4 together, since they all involve the same remote analog throttle circuit and are typically checked in that order.
Could this be a configuration problem instead of a wiring fault?
On OEM applications, yes. The remote analog throttle is configured in the ECU on the Trim page, and if the Trim settings are wrong, the ECU can set this fault even with good wiring and a good throttle. Checking Trim configuration is worth doing before replacing parts.
What should I check first if I get this code?
Start with the remote analog throttle connector and ECU connector for corrosion or loose terminals, then check the harness (including the X5020 connector where equipped) for opens or shorts, then verify Trim configuration on OEM setups. The throttle sensor, ECU software, and ECU itself are further down the list of causes.
Can a bad ECU or ECU software actually cause this code?
Yes, both are listed as possible causes, but they are typically checked after ruling out connectors, harness wiring, and configuration issues, since those are more common and easier to verify first.