Circuit Description
The fuel pump uses an internal check to determine if the fuel injection pump can reach the
commanded timing.
Component Location
The fuel pump circuit is internal to the fuel pump.
Shop Talk
The fuel pump uses pressure generated by an internal vane-type transfer pump and its timing
solenoid to vary the fuel pump’s timing according to the specified ECM commands. Possible causescan be classified into four groups:
1) Static timing – offset key, gear train issues
2) Low-pressure fuel supply issues – restriction issues, low supply pressure
3) Fuel pump return plumbing issues – high return restriction, overflow valve issues
4) Noise in the engine position pulse signal.
Cummins ISB CM550 (1990-94) Fault Code: 367 PID: 370 SPN: FMI: Fuel Pump Speed/Position Sensor Signal Lost
Cummins ISB CM550 (1990-94) Fault Code: 366 PID: 1287 SPN: FMI: Fuel Pump Voltage Measurement Error
Cummins ISB CM550 (1990-94) Fault Code: 365 PID: SID 233 SPN: 1077 FMI: 4 Fuel Pump Voltage Out of Range Error Low
Cummins ISB CM550 (1990-94) Fault Code: 364 PID: SID 233 SPN: 1077 FMI: 9 Engine Control Module (ECM) to Pump Communications Error
Cummins ISB CM550 (1990-94) Fault Code: 364 PID: 1689 SPN: 1077 FMI: 9 Engine Control Module (ECM) to Pump Communications Error
Cummins ISB CM550 (1990-94) Fault Code: 363 PID: SID 251 SPN: 1076 FMI: 7 Fuel Pump Control Valve Feedback Error
