International Fault Code SPN 3242 FMI 18: Aftertreatment 1 Diesel Particulate Filter Intake Temperature: Data Valid But Below Normal Operating Range – Moderately Severe Level

Code details

Manufacturer

International (Navistar)

Applies to

International A26 (2024–2025)

Fault code

SPN 3242 FMI 18

J1939 SPN

3242

FMI

18 — Data valid but below normal range (moderately severe)

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 18 tells the shop the type of failure to test for: data valid but below normal range (moderately severe).
• Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.

Related fault codes

• International Fault Code SPN 3242 FMI 10 — DPFIT Signal – Abnormal Rate of Change
• International Fault Code SPN 3242 FMI 2 — DPFIT Signal – Erratic, Intermittent, or Incorrect
• International Fault Code SPN 3242 FMI 20 — DPFIT Signal – Drifted HIGH
• International Fault Code SPN 3242 FMI 21 — DPFIT Signal – Drifted LOW
• International Fault Code SPN 3242 FMI 3 — DPFIT Signal – Out of Range HIGH
• International Fault Code SPN 3242 FMI 4 — DPFIT Signal – Out of Range LOW
• International Fault Code SPN 3242 FMI 7 — DPFIT Sensor or Circuit Fault
• International Fault Code SPN 3242 FMI 0 — Aftertreatment 1 Diesel Particulate Filter Intake Temperature: Data Valid But Above Normal Operational Range – Most Severe Level