SPN 3264 FMI [0-16] Troubleshooting Explained

SPN 3264 is a diagnostic trouble code for Aftertreatment 1 Diesel Particulate Filter.

FMI 0 – Outlet Gas Temperature Data Valid But Above Normal Operational Range – Most Severe Level
FMI 2 – Outlet Gas Temperature Data Erratic, Intermittent Or Incorrect
FMI 3 – Outlet Gas Temperature Voltage Above Normal, Or Shorted To High Source
FMI 4 – Outlet Gas Temperature Voltage Below Normal, Or Shorted To Low Source
FMI 15 – Outlet Gas Temperature Data Valid But Above Normal Operating Range – Least Severe Level
FMI 16 – Outlet Gas Temperature Data Valid But Above Normal Operating Range – Moderately Severe Level


Troubleshoot:DEF filter, DPF

  • Perform a visual inspection: Check the SCR system components, such as the DEF tank, DEF injector, SCR catalyst, and NOx sensors, for visible damage, leaks, or loose connections.
  • Verify DEF quality and level: Ensure that the DEF is of the correct specification and not contaminated. Also, make sure there is an adequate amount of DEF in the tank.
  • Check for additional fault codes: Use a diagnostic tool to scan the engine control module (ECM) for any additional fault codes that may be related to the SCR system, such as DEF injector or NOx sensor issues.
  • Test the NOx sensors: Verify that the NOx sensors are providing accurate readings by following the manufacturer’s testing procedures, which may involve comparing the sensor output with known good values or using a compatible diagnostic tool.
  • Check the DEF injector: Confirm that the DEF injector is functioning correctly and delivering the appropriate amount of DEF into the exhaust stream. Follow the manufacturer’s testing procedures or use a diagnostic tool to verify its operation.
  • Inspect the SCR catalyst: Examine the SCR catalyst for damage, clogging, or other signs of malfunction. A damaged or clogged catalyst may need to be replaced.
  • Verify repair: After identifying and addressing the cause of the problem, test the system to ensure that the SCR system is working correctly and that the SPN 3264 fault code has been resolved. Clear the fault codes with a diagnostic tool and run the engine to see if the code reappears.