Code Details
| Display code | SPN 110 FMI 0 |
|---|---|
| SPN | 110 |
| FMI | 0 |
| OEM code | None listed |
| Manufacturer | International |
| System | Engine �?cooling system |
| Component | Engine coolant temperature sensor / cooling system |
| Source address | Unknown or not applicable |
| Severity | stop safely |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-11 |
Plain-English Meaning
The International A26 cooling system must manage significant heat from the engine under load. When coolant temperature exceeds the warning threshold, the heat rejection balance has been disrupted. Identifying and resolving the cause quickly prevents head gasket failure and other thermal damage. On International LT Series, RH Series, and HX Series trucks with the A26, the Diamond Logic system provides live coolant temperature data and fan clutch activation control via ServiceMaxx. When coolant temperature rises above normal, ServiceMaxx logs the peak temperature and the engine protection strategy engaged. A common cause on vocational applications is a fan clutch that does not engage at the correct threshold, allowing coolant temperature to continue rising under load. The cooling system on the A26 must be maintained with the correct OAT coolant inhibitor — depletion of inhibitor causes scaling that reduces heat transfer.
SPN 110 FMI 0 is Engine Coolant Temperature above normal. On International A26 engines with the A26 engine management system (Navistar EGR/aftertreatment control), the ECM monitors coolant temperature and manages the fan clutch. International Diamond Logic provides live coolant temperature and fan engagement data for diagnosis.
Common Symptoms
- High coolant temperature warning on the International instrument cluster
- Engine protection derate may activate alongside this fault
- Possible steam or coolant smell in severe cases
- Engine protection derate may activate at sustained high coolant temperature
- Steam or coolant smell if overpressure or overflow occurs
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Low coolant level
- Thermostat stuck closed
- Radiator blocked by debris
- Fan clutch fault
- Water pump failure
- EGR cooler leak adding heat to the coolant circuit
- Fan clutch not engaging at the correct coolant temperature threshold
- Coolant inhibitor depleted causing internal scale reducing heat transfer
First Checks
- Check coolant level in the expansion tank
- Inspect the radiator and charge air cooler faces for airflow blockage
- Connect International Diamond Logic and monitor coolant temperature and fan engagement
- Inspect for external coolant leaks
- Connect ServiceMaxx and verify that the fan clutch activates when commanded and when coolant temperature rises
- Test coolant condition — check inhibitor concentration and freeze point
Can I Keep Driving?
Reduce engine load and stop if temperature continues to rise. Overheating risks permanent engine damage.
Related Codes
Related Lookup Pages
Sources
- International Trucks Service Support Public Resources International Trucks / Navistar International · oem · accessed 2026-06-11 · confidence medium
Source: International Trucks / Navistar International, International Trucks Service Support Public Resources. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - Navistar Engine Diagnostic Trouble Code Body Builder References Navistar / International Truck Body Builder · oem · accessed 2026-05-05 · confidence medium
Source: Navistar / International Truck Body Builder, Navistar Engine Diagnostic Trouble Code Body Builder References. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - SAE J1939 Standards Collection SAE International · official · accessed 2026-05-05 · confidence medium
Source: SAE International, SAE J1939 Standards Collection. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Does the International A26 engine share cooling system components with the MaxxForce 13?
The International A26 is a newer engine design compared to the MaxxForce 13, and it does not share a common cooling system architecture. The A26 uses a more conventional SCR-based emissions approach rather than the high-EGR strategy of the MaxxForce platform, which affects thermal loading on the cooling system differently.
How can I access the International A26 cooling system data without Diamond Logic?
The A26's engine management system communicates over J1939 and OBD-II protocols. A generic heavy-duty J1939 scan tool can read the coolant temperature parameter (SPN 110) and the fault codes. However, DiamondLogic provides additional parameters including fan engagement duty cycle, commanded fan speed, and specific A26 cooling system calibration data that generic tools cannot access.
Is the International LT Series more prone to cooling issues than the ProStar it replaced?
The International LT Series was designed with improved thermal management compared to some earlier ProStar applications. However, any cooling system requires proper maintenance �?coolant level, filter replacement, and radiator cleaning �?regardless of truck generation. Real-world overheating complaints on the LT with A26 are typically maintenance-related or component failures rather than design deficiencies.