John Deere Engines SPN654FMI7 Fault Code: Injector #4 Not Responding
Also called Cylinder #4 EI Fuel Delivery Failure, Cylinder #4 EI Mechanical Failure
Injector #4 Not Responding · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 654 FMI 7 means the ECU expected to see fuel rail pressure drop when cylinder #4's electronic injector fired, and it didn't. This is also described as 'Cylinder #4 EI Mechanical Failure' or 'Injector #4 Not Responding.' The engine will run rough and miss on cylinder #4 while this code is active.
Medium severity. The engine keeps running but will misfire and run rough on cylinder #4. It's not an immediate shutdown risk, but ignoring it wastes fuel, can foul the injector further, and may lead to bigger repair costs if a fuel line or the injector itself is failing. Diagnose within the shift.
What does John Deere Engines error code SPN654FMI7 mean?
This code applies to John Deere diesel engines using electronic injectors (EIs) fed by a high pressure common rail. Each EI is mounted in the cylinder head under the valve cover, spraying straight into the cylinder bore. The ECU controls injection timing and fuel quantity by switching a Two-Way Valve (TWV) inside the injector on and off, which opens and closes the injector's spill valve.
On these engines, power to the injectors is supplied in groups over shared common wires (for example, cylinders 1, 2, and 3 on one wire, and 4, 5, and 6 on another, on 6-cylinder engines), while the ECU switches each injector's individual ground circuit to fire it. When cylinder #4 fires, the ECU expects to see a corresponding drop in fuel rail pressure confirming that fuel was actually delivered.
SPN 654 FMI 7 sets when that expected pressure drop doesn't happen at cylinder #4's injection event. In plain terms, the ECU commanded the injector to fire but saw no evidence that fuel actually went into the cylinder. The direct result is a miss and rough running at that cylinder, since it isn't contributing power like it should.
What triggers a John Deere Engines SPN654FMI7 code?
The ECU sets this code whenever the ignition is on and it fails to detect a drop in fuel rail pressure at the moment cylinder #4 is supposed to inject fuel. There is no listed voltage, pressure, or time threshold, just the presence or absence of the expected pressure drop at that injection event.
Common causes of SPN654FMI7
- Bad terminals or connector at the ECU
- Bad terminals or connector at the EI (injector) wiring harness
- Restricted fuel line between the high pressure common rail (HPCR) and the inlet to the #4 injector, including leaks, pinches, bends, or cracks
- Bad flow limiter
- Bad fuel line fitting at the #4 injector
- Bad fuel inlet connector at the #4 injector
- Loose retaining nuts at the #4 injector
- Bad #4 injector, including a dirty injector or one that fails a fuel leak-off test
- Bad ECU or bad ECU software
- Incorrect high pressure pump timing
- Failed cylinder cutout test or failed cylinder misfire test result pointing to cylinder #4
How to troubleshoot John Deere Engines SPN654FMI7: first checks
- Visually inspect the ECU connectors and the injector harness connector, located at the side of the cylinder head, for contamination, corrosion, damage, or a connector that isn't fully seated
- Check the wiring harness for the #4 injector for chafing, cracked insulation, or damage along its routing, especially near the valve cover and cylinder head
- Inspect the fuel line running from the high pressure common rail to the #4 injector for leaks, pinches, bends, cracks, or restrictions
- Check that the fuel inlet connector and fuel line fitting at the #4 injector are tight and undamaged, and confirm the injector retaining nuts are torqued and not loose
- Run any available cylinder cutout test, cylinder misfire test, or injector fuel leak-off test to confirm whether cylinder #4's injector is actually delivering fuel
- Verify high pressure pump timing is correct if injector and wiring checks come back clean
- If wiring, fuel line, and injector all check good, consider ECU software or a bad ECU as the remaining cause
How the code clears
No separate clearing step is listed. Once the underlying wiring, fuel line, or injector fault is repaired and fuel rail pressure properly drops at cylinder #4's injection event, the code should stop being active. Since the alarm level is listed as a warning tied to an active fault condition, it should clear on its own once the ECU sees a normal pressure drop at that cylinder.
Frequently asked questions
What does SPN 654 FMI 7 mean on a John Deere engine?
It means the ECU expected to see fuel rail pressure drop when cylinder #4's electronic injector fired, but it didn't detect that drop. The engine will run rough and miss at cylinder #4 as a result.
Can I keep driving or running the machine with this code active?
The engine will keep running, but it will misfire and run rough on cylinder #4 since that injector isn't delivering fuel properly. It's best to diagnose and repair it soon rather than run it for extended periods, since a bad injector, fuel leak, or connector issue can get worse.
What's the most common cause of this code?
Possible causes range from bad connectors or terminals at the ECU or injector harness, to a restricted or leaking fuel line to the #4 injector, to a bad injector itself. There's no single most common cause listed, so a methodical check of wiring, fuel lines, and the injector is needed.
Where is the injector harness connector I need to inspect?
It's located at the side of the cylinder head. Check it, along with the ECU connectors, for contamination, damage, or a connector that isn't seated correctly.
Does this code mean the injector itself is bad?
Not necessarily. A bad #4 injector is one possible cause, but so are wiring and connector problems, a restricted or damaged fuel line, a bad flow limiter, loose injector retaining nuts, incorrect high pressure pump timing, or a bad ECU or ECU software. Injector fuel leak-off, cylinder cutout, and misfire tests can help narrow it down.
Is there a specific reset procedure for this code?
No reset procedure is listed for this code. Repairing the underlying wiring, fuel line, or injector issue so the ECU sees a normal pressure drop at cylinder #4's injection event should allow the fault to clear.
When does the ECU check for this fault?
The condition is monitored whenever the ignition is on, and the code is displayed whenever the fault is active during that time.