International Fault Code SPN 109 FMI 4: Engine Coolant Pressure 1: Voltage Below Normal, Or Shorted To Low Source

Code details

Manufacturer

International (Navistar)

Applies to

International A26 (2024–2025)

Fault code

SPN 109 FMI 4

J1939 SPN

109

FMI

4 — Voltage below normal, or shorted to low source

Truck models in source

3200, 4100, 4300, 4400, 7300, 7400, 7500, 7600, 7700, 8500, 8600, BE 200, CE Bus, CXT, DuraStar, LoneStar, MXT, ProStar, RXT, TranStar, WorkStar

What to do next

• Read active and inactive codes with the OEM service tool (Diamond Logic Builder can clear previously active codes) and note the occurrence count.
• FMI 4 tells the shop the type of failure to test for: voltage below normal, or shorted to low source.
• Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.

Related fault codes

• International SA 58 SPN 109 FMI 14 — High Refrigerant Pressure
• International Fault Code SPN 109 FMI 0 — Engine Coolant Pressure 1: Data Valid But Above Normal Operational Range – Most Severe Level
• International Fault Code SPN 109 FMI 1 — Engine Coolant Pressure 1: Data Valid But Below Normal Operational Range – Most Severe Level
• International Fault Code SPN 109 FMI 20 — Engine Coolant Pressure 1: Data Drifted High
• International Fault Code SPN 109 FMI 21 — Engine Coolant Pressure 1: Data Drifted Low
• International Fault Code SPN 109 FMI 3 — Engine Coolant Pressure 1: Voltage Above Normal, Or Shorted To High Source
• Cummins Fault Code 231 — Engine Coolant Pressure Sensor Circuit - shorted high
• Cummins Fault Code 232 — Engine Coolant Pressure Sensor Circuit - shorted low