Circuit Description
This circuit is used for limp home acceleration if communication between the engine control
module (ECM) and fuel pump is lost. The circuit allows for a two-stage acceleration where
there are only two engine speeds available throughout the full range of accelerator travel.
Component Location
This circuit is internal to the fuel pump control module and the engine ECM.
Cummins ISB CM550 (1990-94) Fault Code: 369 PID: 1690 SPN: 1078 FMI: 2 Fuel Pump To Engine Synchronization Pulse Not Recognized
Cummins ISB CM550 (1990-94) Fault Code: 368 PID: SID 254 SPN: 1078 FMI: 8 Fuel Pump Can Not Reach Commanded Timing
Cummins ISB CM550 (1990-94) Fault Code: 368 PID: 216 SPN: 1078 FMI: 8 Fuel Pump Can Not Reach Commanded Timing
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
