Code Details
| Display code | SPN 175 FMI 0 |
|---|---|
| SPN | 175 |
| FMI | 0 |
| OEM code | None listed |
| Manufacturer | International, Navistar |
| System | Engine �?lubrication / cooling |
| Component | Engine oil cooler / cooling system / oil temperature sensor |
| Source address | Unknown or not applicable |
| Severity | high |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-12 |
Plain-English Meaning
The International A26 oil cooler transfers heat from engine oil to the coolant circuit to maintain normal oil temperatures. SPN 175 FMI 0 means the oil temperature sensor in the A26 detected temperatures above the normal operating range. In International LT, HV, and HX series trucks, this is most commonly a cooling system issue �?low coolant, a degraded radiator, or a fan clutch that is not engaging adequately under load. If the cooling system checks out, the A26 oil cooler itself may be fouled with scale.
SPN 175 FMI 0 is Engine Oil Temperature above normal operating range. On International A26 with the integrated powertrain ECM, Diamond Logic Builder displays live oil temperature and coolant temperature simultaneously. Comparing these two values identifies whether the issue is in the oil cooler circuit specifically or in the broader cooling system.
Common Symptoms
- Oil temperature warning on the International instrument panel
- Engine protection derate possible at sustained high oil temperatures
- May occur with elevated coolant temperature in summer heat or on grades
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Cooling system deficiency: low coolant level, failing fan clutch, or restricted radiator
- Internal A26 oil cooler fouled with scale from coolant maintenance deferment
- Thermostat stuck or wrong thermostat specification
- Oil temperature sensor fault
- Extended heavy operation in extreme ambient temperatures
First Checks
- Connect Diamond Logic Builder and compare oil temperature and coolant temperature in real time under load
- Check coolant level and condition �?scale or depleted inhibitors reduce cooling efficiency
- Test fan clutch engagement at operating temperature
- Inspect radiator fins for external debris or internal fouling
- If coolant temperature is normal but oil is high, the oil cooler is the primary suspect
Can I Keep Driving?
The A26 will derate to protect against oil temperature damage. Stop and investigate; do not continue heavy-load operation.
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
Is the International A26 oil cooler internal or external to the engine?
The A26 uses an internal oil cooler integrated into the engine block, using coolant flow through the cooler core to extract heat from the oil. This design means oil cooler fouling requires internal access to clean or replace the cooler core. Diamond Logic Builder can help determine if the oil cooler is the fault by comparing oil and coolant temperature differential under controlled load conditions.
Can SPN 175 FMI 0 on the International A26 cause a no-regen or emissions fault?
High oil temperature typically causes an engine protection derate rather than directly triggering emissions faults. However, the engine protection derate can reduce exhaust temperatures, which may affect DPF regen efficiency. If the derate is severe enough to interrupt a regen cycle, a DPF soot-related fault may appear as a secondary effect. Address the oil temperature issue first.
What coolant type does the International A26 require for proper oil cooler performance?
The A26 requires a heavy-duty coolant meeting the specifications in the International service documentation. Using the correct coolant with proper inhibitor levels is important because scale formation from degraded coolant is a leading cause of oil cooler fouling. Consult the International service documentation or dealer for the specific coolant specification for the A26 application.