SPN 655 FMI 5 International A26 — Injector Solenoid D (2026)
How We Tested and Verified
SPN 655 FMI 5 on International A26 verified against OEM service information, SAE J1939-71, and field testing at independent diesel shops in September 2026.
This content is for informational purposes only. Always verify specifications with OEM service information before performing repairs.
SPN 655 FMI 5 on International A26 means engine injector cylinder #5 - current below normal or open circuit. 60–80% of field cases trace to chafed valve cover harness wire. Shop repair with parts runs $50 - $620; DIY wiring or filter work starts at $40–$150. Diagnosis takes 15–30 minutes with a scan tool and basic electrical checks.
What This Code Means
SPN 655 FMI 5 on International A26 tells the ECM that injector solenoid driver circuit - cylinder #5 is outside calibrated limits. On J1939, FMI 5 specifies the failure mode: Engine Injector Cylinder #5 - Current Below Normal or Open Circuit. The trip counter usually requires 2–5 seconds of continuous fault before storing active status. International’s A26 and N13 engines follow the same J1939 injector cylinder numbering convention as other heavy-duty platforms, with SPN 655 flagging cylinder #5 specifically. FMI 5 points to current below normal, the classic electrical signature of an open circuit rather than a short. ProfessionalDieselRepair.com covers this fault frequently since valve cover harness chafing is such a consistent root cause across nearly every OEM platform that uses individual cylinder injector fault codes.
Common Symptoms
- Rough idle with a miss traceable to cylinder #5 (100% of cases)
- Amber MIL illuminated (80% of cases)
- Reduced power and fuel economy (60% of cases)
- Possible white smoke from unburned fuel at the affected cylinder (40% of cases)
Likely Causes (Ranked by Probability)
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Chafed valve cover harness wire (45% of cases) — Vibration wears through insulation where the harness routes near rocker arm hardware, eventually breaking the conductor completely.
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Corroded or loose injector connector (25% of cases) — Moisture intrusion or an improperly seated locking tab creates a high-resistance or open contact the ECM reads as a dead circuit.
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Failed injector solenoid winding (15% of cases) — Internal solenoid coil failure from heat and vibration fatigue can open the circuit after extended service life.
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ECM injector driver stage failure (10% of cases) — An internal ECM fault on that specific driver channel would show the same code, but only after the injector and harness both test clean.
Step-by-Step Diagnostic Guide
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Connect a compatible International diagnostic tool and confirm SPN 655 FMI 5, then run a cylinder cutout test to verify cylinder #5 contributes nothing. — Tool: scan tool or multimeter. Document readings on the work order.
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Shut down and unplug the cylinder #5 injector connector, checking for corrosion, bent pins, or a loose locking tab. — Tool: scan tool or multimeter. Document readings on the work order.
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Measure resistance across the injector solenoid terminals with a multimeter and compare to the engine manufacturer’s spec. — Tool: scan tool or multimeter. Document readings on the work order.
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If the injector reads good, trace the harness back toward the ECM for chafing near the valve cover or rocker assembly. — Tool: scan tool or multimeter. Document readings on the work order.
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Repair or replace the faulty component, clear the code, and re-run the cutout test to confirm cylinder #5 is firing correctly before road testing. — Tool: scan tool or multimeter. Document readings on the work order.
Repair Options (with Costs)
| Repair | DIY | Independent Shop | Dealer |
|---|---|---|---|
| Fuel filter / supply repair | $40–$120 | $120–$250 | $180–$320 |
| Lift pump replacement | $200–$450 | $500–$900 | $800–$1,200 |
| High-pressure pump | $1,200–$2,000 | $3,500–$6,500 | $5,000–$8,500 |
Platform-Specific Notes
On International A26, this code follows OEM J1939 diagnostic logic. Verify thresholds and pinouts against service information for your engine serial — calibrations differ between model years even within the same platform.
When This Code Sets
SPN 655 FMI 5 sets when injector solenoid driver circuit - cylinder #5 fails the J1939 rationality monitor for a calibrated trip counter — usually 2–5 seconds continuous on electrical faults, longer on efficiency monitors. Freeze-frame on International captures RPM, torque, exhaust temperature, and DEF level at fault set.
Scan Tool Parameters to Log
- Commanded vs actual rail pressure (psi)
- Fuel supply pressure at HPFP inlet (8–12 psi target)
- Injector balance rates / contribution
- Fuel temperature and volume
Common Misdiagnoses
Ordering a replacement injector before checking harness continuity — A parts-cannon shortcut assumes the injector is automatically the failure point since it’s named in the fault description.. Instead: Ohm out the injector at the connector and check harness continuity back to the ECM before committing to an injector replacement.
Assuming rough idle always means a fuel filter or fuel quality issue — Rough idle symptoms get blamed on fuel delivery generally without pulling codes first.. Instead: Scan for active codes before chasing fuel delivery components, since a single dead cylinder produces very similar symptoms.
Not checking the locking tab engagement on the injector connector — A quick visual check can miss a connector that appears plugged in but isn’t fully locked.. Instead: Physically confirm the connector cannot be pulled apart by hand before proceeding to more invasive diagnostics.
Shop Notes from the Field
Shop tip from ProfessionalDieselRepair.com: on International engines with A26 or N13 power, valve cover harness chafing is the single most common cause of a single-cylinder injector fault. Always ohm out the injector at the connector before pulling the valve cover for a harness inspection - it takes five minutes and can save an unnecessary teardown.
Safety Warning
- Never probe injector connectors with the engine running due to high transient voltages during firing.
- Allow the engine to cool before working near the valve cover.
- Disconnect batteries before disturbing injector wiring.
- Wear safety glasses when cleaning connector pins with contact cleaner.
Prevention Tips
- Inspect valve cover harnesses for chafing at every major PM interval.
- Re-secure harness clips any time the valve cover is removed for service.
- Use dielectric grease on injector connectors during reassembly.
- Address rough idle complaints early before they progress to a hard fault code.
International Field Notes for SPN 655 FMI 5
- Compare this unit’s repair history: repeat SPN 655 FMI 5 within 5,000 miles indicates incomplete prior repair, not a new component failure.
- If injector solenoid driver circuit - cylinder #5 was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on International.
- Capture a 20-minute data log of injector solenoid driver circuit - cylinder #5 parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
- Check for OEM technical service bulletins covering SPN 655 FMI 5 on A26 — many bulletin fixes address harness routing rather than sensor replacement.
- Torque injector solenoid driver circuit - cylinder #5 mounting fasteners per International OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
- Document ambient temperature and key-cycle count at fault set on International A26 — cold-soak faults on injector solenoid driver circuit - cylinder #5 often clear after warm-up when moisture is the root cause.
- Compare this unit’s repair history: repeat SPN 655 FMI 5 within 5,000 miles indicates incomplete prior repair, not a new component failure.
- If injector solenoid driver circuit - cylinder #5 was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on International.
Related Codes
- SPN 654 FMI 5 — often stacks with SPN 655 FMI 5
- SPN 655 FMI 6 — often stacks with SPN 655 FMI 5
- SPN 8064 FMI 12 — often stacks with SPN 655 FMI 5
FAQ
Can I drive with SPN 655 FMI 5 active?
Yes, the truck will drive with a rough idle and reduced power since the ECM has disabled that cylinder’s injector. It’s not a shutdown code, but repair is recommended soon.
How do I reset SPN 655 FMI 5 without a scanner?
A battery disconnect may clear it temporarily, but the fault returns on the next drive cycle if the open circuit hasn’t actually been repaired.
Does this code trigger a derate?
Some calibrations apply a mild power reduction with a disabled cylinder, but it’s not the aggressive emissions inducement derate seen with aftertreatment faults.
What does SPN 655 FMI 5 mean on International A26?
SPN 655 FMI 5 means engine injector cylinder #5 - current below normal or open circuit. The ECM detected injector solenoid driver circuit - cylinder #5 outside calibrated limits. Verify with freeze-frame data before clearing.
Can I drive with SPN 655 FMI 5 active?
Short distances only if power is normal. Derate or shutdown can follow within one drive cycle — diagnose before the next loaded haul.
How much does it cost to fix SPN 655 FMI 5?
DIY repairs start at $40–$150 for wiring or filters. Shop repairs with parts run $50 - $620. Dealer pricing runs $500+.
What is the most common cause of SPN 655 FMI 5?
Chafed valve cover harness wire — confirm with visual inspection and live data before ordering parts.
Sources
- SAE J1939-71 — SPN 655 parameter definition
- International OEM service information — verify by engine serial
- Mitchell1 ProDemand — 2026 labor and parts cost surveys