Circuit DescriptionThe 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 temperaturesensors. Component LocationThe +5-VDC sensor supply circuit is located in the sensor harness. Refer to Procedure 100-002 (Engine Diagrams) in Section E for the sensor locations. Shop TalkThese faults could also cause high-voltage or low-voltage faults on the coolant temperature and intake manifold temperature sensors. Cummins ISB CM550 (1990-94) Fault Code: 349 PID: 191...

Circuit DescriptionThe 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 temperaturesensors. Component LocationThe +5-VDC sensor supply circuit is located in the sensor harness. Refer to Procedure 100-002 (Engine Diagrams) in Section E for the sensor locations. Shop TalkThese faults could also cause high-voltage or low-voltage faults on the coolant temperature and intake manifold temperature sensors. Cummins ISB CM550 (1990-94) Fault Code: 352 PID: SID...

Circuit DescriptionThis circuit is internal to the fuel pump control module. Component LocationThe fuel pump control valve is inside the fuel pump. Shop TalkThis fault is set when the fuel-metering solenoid valve is energized continuously or if current is detected at the fuel control solenoid while the pump incremental angle sensor detects thesynchronization gap of the fuel pump tone wheel. Voltage irregularities and electrical noise can trigger Fault Code 361. Check for low battery voltage or loose pins (pins 6 and 7 of the pump harness connector). Cummins ISB CM550 (1990-94) Fault Code: 352 PID: SID 232 SPN: 620 FMI:...

Circuit DescriptionThis circuit is internal to the fuel pump control module. It controls the quantity of fuel beingdelivered to each cylinder. Component LocationThe fuel-metering valve is located inside the fuel pump in the middle of the delivery valveholders. Shop TalkThis fault is set when the fuel-metering solenoid valve quick dissipation voltage is too low.Fault Code 362 can be triggered by power supply glitches or voltage spikes. Additionally,current or clamping voltage outside the set limits can trigger this fault code. Cummins ISB CM550 (1990-94) Fault Code: 361 PID: 254 SPN: FMI: Fuel Valve Control High Current Error Cummins ISB CM550 (1990-94)...

Circuit DescriptionThis circuit is internal to the fuel pump control module. It controls the quantity of fuel beingdelivered to each cylinder. Component LocationThe fuel-metering valve is located inside the fuel pump in the middle of the delivery valveholders. Shop TalkThis fault is set when the fuel-metering solenoid valve quick dissipation voltage is too low.Fault Code 362 can be triggered by power supply glitches or voltage spikes. Additionally,current or clamping voltage outside the set limits can trigger this fault code. Cummins ISB CM550 (1990-94) Fault Code: 362 PID: 253 SPN: 1076 FMI: 4 Fuel Valve High Current Error Cummins ISB CM550...