Code Details
| Display code | SPN 102 FMI 1 |
|---|---|
| SPN | 102 |
| FMI | 1 |
| OEM code | None listed |
| Manufacturer | International, Navistar |
| System | Engine �?turbocharger / air handling |
| Component | Turbocharger / VGT actuator / CAC / boost sensor |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-11 |
Plain-English Meaning
The A26 turbocharger is a variable geometry turbo (VGT) that changes vane position to control boost. When boost falls below what the ECM expects for the current throttle and speed conditions, this fault sets. Low boost means less air for combustion, reducing power and increasing smoke. The most common causes on the A26 are a VGT actuator fault, a charge air cooler or intercooler leak, or an air filter restriction. On International LT Series and RH Series trucks, the A26 turbocharger is a variable geometry unit controlled by Diamond Logic. ServiceMaxx displays VGT actuator position, boost pressure, and compressor outlet temperature in a single screen. A boost pressure fault on the A26 that is accompanied by visible blue or white smoke may indicate a turbocharger seal issue that is allowing oil or coolant into the intake — this should be evaluated before performing a boost leak test under pressure, as pressurizing a compromised turbocharger can exacerbate the seal failure.
SPN 102 FMI 1 is Boost Pressure below normal range. On International A26 with ACM2.1 aftertreatment module and the integrated powertrain ECM, Diamond Logic Builder or JPRO can monitor actual boost pressure, VGT vane position, VGT actuator commanded position, and air flow. A VGT actuator that is mechanically correct but not moving to commanded position typically points to a carbon-fouled actuator or gear failure in the actuator drive.
Common Symptoms
- Reduced engine power and torque
- Black or grey smoke under load
- Sluggish throttle response
- Higher exhaust temperatures
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- VGT actuator stuck or not responding to commands
- Charge air cooler or intercooler hose leak
- Restricted air filter
- Boost pressure sensor fault
- Turbocharger mechanical wear
First Checks
- Connect Diamond Logic Builder or JPRO and command the VGT actuator through its range to test responsiveness
- Inspect all intercooler and charge air cooler connections for loose clamps or cracked hoses
- Check air filter restriction indicator
- Compare actual vs. expected boost pressure across the load range in live data
- Check for companion turbocharger fault codes in ServiceMaxx before performing a pressurized boost leak test
- Inspect the intercooler and charge air pipes for oil residue that would indicate a turbocharger seal issue
Can I Keep Driving?
Driveable but with reduced power. Continued operation with low boost increases smoke and exhaust temperatures.
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
Is the A26 VGT actuator the same design as on earlier International engines like the MaxxForce?
The International A26 is a Navistar-designed engine introduced from 2017. It uses an electronically controlled VGT. The actuator design is different from the MaxxForce 13 and earlier International engines. Part numbers and service procedures are specific to the A26 platform. Diamond Logic Builder or the International Service Portal provides the correct A26-specific information.
Can a clogged DPF cause SPN 102 FMI 1 boost pressure low on the A26?
A severely restricted DPF increases exhaust backpressure, which can reduce turbocharger efficiency and apparent boost. While the DPF is not a direct cause of low boost pressure in the same way as a VGT fault or intercooler leak, extreme DPF restriction does affect turbo performance. If the DPF pressure differential is also elevated, address the DPF restriction as part of the diagnosis.
How do you distinguish a VGT actuator fault from a turbocharger mechanical fault on the A26?
Use Diamond Logic Builder or JPRO bidirectional test to command the VGT actuator open and closed. If the actuator position feedback matches the commanded position (the actuator moves as commanded), the actuator itself is functional and the low boost may be from turbocharger bearing wear, wheel damage, or a leak elsewhere. If the actuator does not reach its commanded position, the actuator or linkage is the fault.