SPN 1569 FMI 31: Engine Torque Derate

What SPN 1569 identifies

SPN 1569 reports engine-protection torque derate. In the cited Cummins/Blue Bird guide, 1569/FMI 31 maps to FC 3714. It reports the reduction in available torque; the associated fault list is needed to determine why it occurred. Blue Bird SU2103 / Shaw 0000297252, revision B (2021)

Documented SPN/FMI example

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Examples only; a dash means no separate FC is supplied here. *See source applicability below; a model name alone does not establish calibration coverage.

Find the reason for the derate

1. Save every active and inactive fault, the reporting controller and available operating data before clearing anything.
2. Identify the initiating condition using the OEM fault information. Do not assume that an aftertreatment fault is the only possible engine-protection concern.
3. Repair and verify the initiating fault using the prescribed procedure. Run a regeneration only when that procedure calls for it and the prerequisites are satisfied.
4. Recheck the fault list and the indicated derate status. An inactive code and restored operation should be documented together.

SPN 5246 identifies SCR inducement severity. Torque reduction and a vehicle-speed restriction are different observations; record both rather than treating 1569 as shorthand for a fixed speed limit.

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