Do not driveMinutes
J1939 code SPN 109. Below — how the fault is worded at the factory by International, and what the second half of the code (FMI) means in the standard.
| FMI 14 | Coolant Pressure — High Refrigerant Pressure |
| SPN 109 FMI 14109/14 · 109.14 | manufacturer-specific instructions |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The engine is already past its temperature limit. An aluminium head goes fast: first the geometry warps, then the gasket burns through.
Next comes a blown head gasket, a damaged head and, at worst, a cracked block. Shut it down and let it cool — never open the expansion tank cap while hot.
Let the engine cool — never open the expansion tank cap while hot. Then check the level and the hoses.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.