International (Navistar)
J1939 SPN/FMI
SPN 3242 / FMI 21
International Fault Code SPN 3242 FMI 21: DPFIT Signal – Drifted LOW
SPN 3242 FMI 21 on International / Navistar trucks means: DPFIT Signal – Drifted LOW.
Code details
- Manufacturer
- International (Navistar)
- Applies to
- International MaxxForce DT (2010–2019)
- Fault code
- SPN 3242 FMI 21
- J1939 SPN
- 3242
- FMI
- 21
- 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 21 tells the shop the type of failure to test for: .
- Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.
Get this code diagnosed
Send one request and nearby diesel shops and mobile mechanics can quote the repair.
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Related fault codes
- International Fault Code SPN 3242 FMI 21 — Aftertreatment 1 Diesel Particulate Filter Intake Temperature: Data Drifted Low
- 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 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
Source: International MaxxForce DT 2010–2019 fault code list (Diesel Laptops). See also OBD-II codes.