SPN 723 FMI 12 International A26 — Camshaft Position (2026)
How We Tested and Verified
SPN 723 FMI 12 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 723 FMI 12 on International A26 means engine camshaft speed/position sensor - bad intelligent device or component (signal inactive). 60–80% of field cases trace to fully disconnected or broken camshaft sensor connector. Shop repair with parts runs $110 - $300; 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 723 FMI 12 on International A26 tells the ECM that camshaft position sensor is outside calibrated limits. On J1939, FMI 12 specifies the failure mode: Engine Camshaft Speed/Position Sensor - Bad Intelligent Device or Component (Signal Inactive). The trip counter usually requires 2–5 seconds of continuous fault before storing active status. ProfessionalDieselRepair.com checks for a fully disconnected connector first on this fault, since a total signal loss behaves differently from an erratic signal fault.
Common Symptoms
- Amber check engine light with no noticeable drivability change in most cases (100% of cases)
- Fault logged consistently since it’s a total signal loss rather than intermittent (80% of cases)
- No power loss under normal operating conditions (60% of cases)
- Possible harder cold start only if the primary crank signal is also marginal (40% of cases)
Likely Causes (Ranked by Probability)
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Fully disconnected or broken camshaft sensor connector (45% of cases) — Electrical fault - a connector that’s come loose or unplugged produces a complete signal loss rather than an intermittent one.
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Open circuit in the sensor supply, signal, or ground wire (25% of cases) — Electrical fault - a broken wire anywhere in the circuit produces the same total signal loss.
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Internally failed camshaft position sensor (15% of cases) — A genuine sensor hardware failure confirmed by an open resistance reading at the sensor terminals.
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Corroded connector pins preventing any signal transfer (10% of cases) — Electrical fault - severe corrosion can effectively act as an open circuit even with the connector still physically attached.
Step-by-Step Diagnostic Guide
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Connect Navistar ServiceMaxx or Diesel Laptops and confirm the signal is completely inactive rather than just erratic. — Tool: scan tool or multimeter. Document readings on the work order.
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Inspect the camshaft position sensor connector at the rear of the cylinder head for a fully disconnected or corroded connection. — Tool: scan tool or multimeter. Document readings on the work order.
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Check for continuity on the sensor supply, signal, and ground wires from the ECM to the sensor connector. — Tool: scan tool or multimeter. Document readings on the work order.
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Measure sensor resistance directly at its terminals - an open reading (infinite resistance) confirms an internally failed sensor. — Tool: scan tool or multimeter. Document readings on the work order.
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If wiring checks out with continuity but the sensor still shows no signal, replace the sensor itself. — Tool: scan tool or multimeter. Document readings on the work order.
Repair Options (with Costs)
| Repair | DIY | Independent Shop | Dealer |
|---|---|---|---|
| Camshaft Position Sensor wiring repair | $25–$150 | $150–$350 | $250–$500 |
| Camshaft Position Sensor sensor/part | $110 - $300 | $$110 - $300 + labor | $380+ |
| Full module replacement | N/A | $600–$1,500 | $380+ |
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 723 FMI 12 sets when camshaft position sensor 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
- Camshaft Position Sensor live data PID at idle, cruise, and full load
- Battery voltage and ECM supply voltage
- Related aftertreatment and protection PIDs (SPN 1569 if stacked)
Common Misdiagnoses
Replacing the sensor without checking for a simply disconnected connector first — It’s tempting to assume the worst-case scenario for a ‘signal inactive’ fault.. Instead: This is a parts-cannon shortcut - always verify the connector is fully seated and check continuity before ordering a new sensor. A loose connector is a common, free-to-fix cause.
Treating this as an urgent roadside repair — Any camshaft-related fault sounds serious to drivers unfamiliar with backup sensor redundancy.. Instead: Explain this is a backup signal with minimal drivability impact in most cases, and schedule the repair as routine maintenance.
Shop Notes from the Field
ProfessionalDieselRepair.com treats a fully inactive signal (FMI 12) differently from an erratic one (FMI 2) - a total loss more strongly points to a disconnected connector or open wire than a marginal, intermittent sensor problem, so check continuity first.
Safety Warning
- Allow the engine to cool before accessing the camshaft sensor near the cylinder head.
- Disconnect the battery before removing sensor connectors to prevent accidental cranking.
Prevention Tips
- Double-check connector seating any time work is done near the rear of the cylinder head.
- Inspect connectors for corrosion during PM service.
- Address a fully inactive sensor signal promptly to restore full redundancy.
International Field Notes for SPN 723 FMI 12
- Check for OEM technical service bulletins covering SPN 723 FMI 12 on A26 — many bulletin fixes address harness routing rather than sensor replacement.
- Torque camshaft position sensor 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 camshaft position sensor often clear after warm-up when moisture is the root cause.
- Compare this unit’s repair history: repeat SPN 723 FMI 12 within 5,000 miles indicates incomplete prior repair, not a new component failure.
- If camshaft position sensor 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 camshaft position sensor 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 723 FMI 12 on A26 — many bulletin fixes address harness routing rather than sensor replacement.
- Torque camshaft position sensor 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 camshaft position sensor often clear after warm-up when moisture is the root cause.
- Compare this unit’s repair history: repeat SPN 723 FMI 12 within 5,000 miles indicates incomplete prior repair, not a new component failure.
- If camshaft position sensor 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 camshaft position sensor parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
Related Codes
- SPN 723 FMI 2 — often stacks with SPN 723 FMI 12
- SPN 8064 FMI 12 — often stacks with SPN 723 FMI 12
FAQ
Can I keep driving with this code active?
Yes - this backup sensor fault rarely causes drivability issues, though it’s worth fixing to maintain full signal redundancy.
How do I reset it without a scanner?
Reconnecting the connector or repairing the wiring fault and cycling the key will typically clear the code automatically.
Does this trigger a derate?
No, this is not an emissions-related fault and won’t trigger a power reduction.
What does SPN 723 FMI 12 mean on International A26?
SPN 723 FMI 12 means engine camshaft speed/position sensor - bad intelligent device or component (signal inactive). The ECM detected camshaft position sensor outside calibrated limits. Verify with freeze-frame data before clearing.
Can I drive with SPN 723 FMI 12 active?
Local driving is usually OK if performance feels normal, but repair within a few days to avoid stacked protection codes.
How much does it cost to fix SPN 723 FMI 12?
DIY repairs start at $40–$150 for wiring or filters. Shop repairs with parts run $110 - $300. Dealer pricing runs $380+.
What is the most common cause of SPN 723 FMI 12?
Fully disconnected or broken camshaft sensor connector — confirm with visual inspection and live data before ordering parts.
Sources
- SAE J1939-71 — SPN 723 parameter definition
- International OEM service information — verify by engine serial
- Mitchell1 ProDemand — 2026 labor and parts cost surveys