Cummins ISB CM550 (1990-94) Fault Code: 375 PID: SID 254 SPN: FMI: 2 Engine Control Module (ECM) Fuel Calibration Corrupted

Circuit Description
The ECM contains the calibration-specific parameter to control the engine’s performance and diagnostics. The fuel pump has its own calibration to interpret the ECM message and control
the pump. If the fueling calibration in the ECM is altered or tampered with, this fault will be
logged.

Component Location
The logic for the fault code is contained in the ECM circuitry.

Shop Talk
This fault code is meant to detect out-of-range values and protect the fuel pump from
excessive duty cycles from illegal calibration tampering. If this code is active or has high inactive counts, the fuel pump control module has detected an out of range value commanded by the ECM. Recalibrate the ECM.