SPN 1569 DTC Troubleshooting

SPN 1569 FMI 31 is a diagnostic trouble code for engine protection torque derate.

DEF sensors, update ECM

Common FMI codes associated with SPN 1569 include:

  • FMI 31: Engine derate condition – The engine control module (ECM) has detected a problem with the DPF and has limited the engine power to protect the system from further damage.
  • FMI 20: Data erratic or intermittent – The ECM is receiving inconsistent information from the DPF system, which may be caused by a faulty sensor, wiring issue, or other problems.

more codes: