John Deere Engines SPN653FMI5 Fault Code: Injector #3 Circuit Has High Resistance
Also called Cylinder #3 EI Circuit Open, Cylinder #3 EUI Circuit Open, Electronic Unit Pump #3 Circuit Has High Resistance, Injector #2 Circuit Has High Resistance, Injector #3 Spill Valve Circuit Has High Resistance
Injector #3 Circuit Has High Resistance · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 653 FMI 5 means the ECU sees an open or high-resistance condition in the cylinder #3 injector circuit, whether that engine uses electronic unit injectors (EUI), electronic injectors (EI), or common-rail injectors. When it sets, cylinder #3 stops firing or the ECU flags high resistance in that injector's ground or supply path, while trying to keep running the engine normally.
Medium severity. The engine will typically keep running since the ECU attempts normal control, but a dead or high-resistance cylinder #3 injector circuit causes a misfire on that cylinder, lost power, rough running, and possible long-term wear from unburned fuel or uneven load. Diagnose it before it triggers a related high-resistance code on another injector circuit sharing the same supply wire.
What does John Deere Engines error code SPN653FMI5 mean?
SPN 653 FMI 5 points to the cylinder #3 injector circuit on John Deere diesel engines. Depending on engine family, this circuit feeds an electronic unit injector (EUI, used on 10.5 L and 12.5 L engines), an electronic injector (EI, used on the 8.1 L engine with a two-way valve controlling the spill valve), or a common-rail electronic injector on other displacements. In every case, the ECU controls firing by switching the low side (ground) of the injector circuit on and off while a shared high wire supplies power to a bank of three cylinders.
FMI 5 specifically means the ECU is seeing an open circuit or added resistance rather than a short or an out-of-range signal. On the EUI and EI systems this is described as an open in the cylinder #3 circuit, meaning that injector will not fire at all. On common-rail systems the ECU instead describes it as high resistance, which can be caused by a true open circuit or by just a few extra ohms of resistance anywhere in the #3 injector wiring, and it can also cause related high-resistance codes on other injectors that share the same high-voltage supply wire.
Because cylinders are wired in two banks of three, sharing a common power wire, a wiring fault upstream of cylinder #3 can affect its neighbors on the same bank as well. That is why the troubleshooting sequence for the common-rail version starts with checking SPN 627 FMI 1 before working SPN 653 FMI 5.
Common causes of SPN653FMI5
- Bad terminals or connector at the ECU (48-way connector on EUI systems, 12-way on 6.8L, or 6-way on 4.5L systems)
- Bad terminals or connector at the EUI or EI harness connector, located at the back or side of the cylinder head, or at the injector connector on common-rail systems
- Open or short in the wiring harness between the ECU and the injector harness, including the main harness
- Bad #3 injector, EUI, or EI solenoid/two-way valve itself
- Bad injector wiring harness in the cylinder head
- Open or short in the 90V circuit (EI systems)
- Bad ECU software
- Bad ECU
How to troubleshoot John Deere Engines SPN653FMI5: first checks
- Visually inspect the ECU connector (48-way, 12-way, or 6-way depending on engine) for dirty, damaged, corroded, or poorly seated terminals
- Inspect the injector or EUI/EI harness connector at the cylinder head for contamination, damage, or poor positioning
- Check the wiring harness between the ECU and the injector connector for chafing, pinches, opens, or shorts, paying attention to any section running near heat or moving parts
- On common-rail engines, run the Harness Diagnostic Mode Test in Service ADVISOR, but only after confirming fuel rail pressure is below 5 MPa (725 psi)
- Check SPN 627 FMI 1 first if it is also active, since it shares the injector high-voltage supply circuit with SPN 653 FMI 5
- Check the #3 injector or EUI/EI itself for continuity if wiring and connectors check out
How the code clears
No separate clearing step is listed. Once the open circuit or high-resistance connection is repaired and verified, the code should stop being active on the next key cycle or engine run. No reset procedure beyond the repair is listed for this code.
Frequently asked questions
What does SPN 653 FMI 5 mean on a John Deere engine?
It means the ECU detected an open circuit or high resistance in the wiring that fires the cylinder #3 fuel injector, whether that is an electronic unit injector, an electronic injector, or a common-rail injector depending on the engine.
Will the engine still run with SPN 653 FMI 5 active?
The ECU will attempt to control the engine in a normal manner, but cylinder #3 will not fire correctly or at all, which usually shows up as a misfire, rough idle, or power loss.
Is SPN 653 FMI 5 the same on every John Deere engine?
No. The wording differs by engine family. On 10.5 L and 12.5 L engines it involves the EUI circuit, on the 8.1 L engine it involves the EI circuit and two-way valve, and on other engines with common-rail injection it is described as high resistance in the injector circuit.
Why does this code sometimes come with a code on a different cylinder?
Cylinders 1, 2, and 3 share one common power wire, and cylinders 4, 5, and 6 share another. An open in that shared high-voltage supply can trigger high-resistance codes on more than one injector circuit at the same time.
What should I check first for SPN 653 FMI 5?
Start with a visual inspection of the ECU connector and the injector or EUI/EI harness connector at the cylinder head, looking for corrosion, damage, or poor terminal fit, then check the harness wiring in between.
Can a bad ECU cause this code?
Yes, a bad ECU or bad ECU software is listed as a possible cause, but it should be considered only after ruling out connectors, harness wiring, and the injector itself.
Do I need special tools to diagnose this code?
On common-rail engines, Service ADVISOR's Harness Diagnostic Mode Test can help, but it must only be run when fuel rail pressure is below 5 MPa (725 psi) for safety and accurate readings.