Cummins IS – Interact System & HPI-TP Fuel System

Cummins IS – Interact System & HPI-TP Fuel System

Introduction

Cummins 3rd generation of electronics was introduced in 1997 under the IS management system. ISX CM870 engine control system

The Electronic Control Module is the control center of the system. The ECM processes all of the inputs and sends commands to the fuel system, vehicle, and engine control devices. Because the ECM is the final pathway of integration for all vehicle management systems, it is called interact or IS for short.

IS From Cummins includes some of the following features  Faster processing speeds and increased memory  Improved fuel efficiency  Integrated Centinel Control (no separate module)  Improved Maintenance Monitor features  Enhanced PTO programming features/ parameters  Enhanced engine diagnostics/Prognostics  Enhanced Security features

y Audit trails

y Enhanced Engine Protection System  Anti theft protection when used with Road Relay  Powertrain Protection Features  J-1939 Network capable  Enhanced On-Board Trip Information

y Battery Powered ECM clock back-up for real time clock stamping of data.

y Enhanced data reporting features

y Short Range Radio Communication (“Inrange” SRRF) System  Improved Emission Reduction

“INRANGE” SRRF System) Fault codes can be retrieved, the ECM recalibrated etc. using this tool.

Cummins small medium and large bore engines received this new system after the

CELECT system. Instead of the B, C, L, and M engines, their new names are ISB, ISC, ISL, ISM.ISX and Signature

The N-14 kept Celect Plus system but will not be produced after 2000 model year

CM870 ECM Features

The most significant change from the CELECT system is the new ECM module. It was originally the air cooled CM570. It had a greater number of inputs and output pins than CELECT PLUS - all of which are programmable. Many more features and components can be added to this system which can interface with J-1939 network and PWM outputs.

The newest ECM is the CM870 introduced in the ‘02 model year. This system has advanced capabilities to control the EGR system and the variable geometry (VGT) turbocharger

The ECM contains the software code to run the engine and can be powered by either a 12 or 24 volt system.

The ECM also provides the ability to communicate with service tools and contains memory for data storage.

The ECM communicates with service tools and some other vehicle controllers, such as transmissions, braking system, and traction control systems, through an SAE J1939 and the 1708/1587 Datalink.

The ECM determines the power output of individual cylinders by the way the engine speed increases due to a combustion event. The ECM averages this instantaneous power output of a single cylinder over a number of cylinder firings. The ECM then decides what adjustments to make to the fueling on each cylinder to balance the power equally between cylinders.

The ECM is mounted to a cooling plate on the fuel pump side of the engine. Fuel flow through a passage in the cooling plate provides the necessary cooling for the ECM. About 35% of the output of the gear pump is sent through this cooling plate.

Above: Note ECM cooling plate and connectors

HPI-TP Fuel System

Heavy Duty High Pressure Injection - Time Pressure Fuel System

Cummins ISX/Signature (Signature has a different heavier premium parts system) uses a new fueling system on ISX and Signature 600 engine. The injector uses an open nozzle style of injector used on earlier PT systems. The design of this nozzle maintains that “old PT system sound” to it as a result. (open nozzle do not use a valve closing needle valve but instead allow combustion gases to mix in the injector cup before the plunger pushes the fuel/air mixture out the orifice).

Timing and metering pressure-regulating solenoids/actuators now control hydraulic circuits to the injectors. Metering solenoids control fuel quantity at the timing solenoids control the beginning and end of injection.

1. Fuel Supply from Tank 7. Timing Actuator

2. Fuel Lift Pump 8. Fueling Supply to Injector

3. Fuel Pump 9. Timing Fuel Supply to Injector

4. Pressure Fuel Filter 10. Injector

5. Fuel Shutoff Valve 11. Fuel Drain to Tank.

6. Fueling Actuator

The operation of the centrally located injector is also unique. Metering and timing plungers in the injector are operated hydraulically using fuel supplied to it through separate timing and metering rails located in the cylinder head. Pressurization of the fuel for injection is accomplished by a plunger actuated by an overhead camshaft. Note there are no electrical connections or solenoids on the injector.

Integrated Fuel System Module (IFSM)

The system consists of six high-pressure unit injectors and an integrated fuel system module (IFSM) containing actuators that provide various fuel pressure for metering and timing control of the injectors. PWM signals to the actuators control injection quantity and injection timing, a pump and regulator for fuel supply pressure, a 10 micron pressure side filter, and

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