Circuit Description
The engine position sensor (EPS), the intake manifold pressure sensor, and the oil pressure
sensor are powered by the same +5-VDC source and the same return in the electronic control
module (ECM). This supply is also used to operate the intake manifold temperature and
coolant temperature sensors.
Component Location
The +5-VDC sensor supply circuit is located in the sensor harness. See Section E of this
manual for the sensor locations.
Shop Talk
These faults could also cause high- or low-voltage faults on the coolant temperature and intake
manifold temperature sensors.
Cummins ISB CM550 (1990-94) Fault Code: 386 PID: SID 232 SPN: 620 FMI: 3 Sensor Suppy Circuit
Cummins ISB CM550 (1990-94) Fault Code: 385 PID: SID 232 SPN: 620 FMI: 1 Remote Accelerator Supply Circuit
Cummins ISB CM550 (1990-94) Fault Code: 385 PID: SID 232 SPN: 620 FMI: 3 Remote Accelerator Supply Circuit
Cummins ISB CM550 (1990-94) Fault Code: 382 PID: SID 237 SPN: 626 FMI: 11 Intake Air Heater Relay Circuit
Cummins ISB CM550 (1990-94) Fault Code: 381 PID: SID 237 SPN: 626 FMI: 11 Intake Air Heater Relay Circuit
Cummins ISB CM550 (1990-94) Fault Code: 377 PID: SID 233 SPN: 107 FMI: 7 Fuel Pump Power Relay Stuck-On