Cummins ISLe CM850 Wiring Diagram | ECM Pinout, Sensors & J1939 Network (4021598)

Coverage

• ECM wiring (engine harness and OEM connector)
• Injector driver circuits (6 cylinders)
• Engine sensor network with 5V supply architecture
• Fuel system (rail pressure, pump actuator, lift pump)
• Cooling and monitoring sensors
• Aftertreatment system (NOx sensor, catalyst system)
• Catalyst solution tank and heater system
• SAE J1939 CAN data link
• SAE J1587 data link
• Diagnostic connectors (8-pin and 9-pin Deutsch)
• Accelerator pedal and control switches
• Dashboard warning lamps and outputs

Technical Highlights

• Full ECM pinout with detailed signal mapping
• 6-cylinder injector control architecture
• Integrated aftertreatment catalyst system
• Dual communication networks (J1939 + J1587)
• Color-coded wiring system for easy tracing
• Battery, ignition, and fuse-protected circuits
• OEM vs Cummins responsibility separation
• Support for multiple accelerator pedal configurations

Table of Content

• Wiring Diagram Overview
  • Signal Legend and Color Codes
  • Wiring Symbols and Pin Identification
• Power Distribution
  • Battery Supply
  • Ignition Input
  • Fuse Protection
• Engine Control Module (ECM)
  • ECM Overview
  • Engine Harness Connector
  • OEM Harness Connector
• Engine Sensors
  • Crankshaft Speed Sensor
  • Camshaft Position Sensor
  • Fuel Rail Pressure Sensor
  • Intake Manifold Pressure / Temperature Sensor
  • Barometric Pressure Sensor
  • Coolant Temperature Sensor
  • Oil Pressure Switch
  • Oil Level Sensor
  • Water in Fuel Sensor
• Fuel System
  • Fuel Pump Actuator
  • Fuel Lift Pump
  • Injector Circuits (1–6)
• Aftertreatment System
  • NOx Sensor
  • Catalyst Solution Tank
  • Catalyst Heater System
  • Exhaust Gas Temperature Sensors
• Vehicle Interface (OEM Side)
  • Accelerator Pedal Configurations
  • Cruise Control and PTO Switches
  • Brake and Clutch Switches
  • Fan and AC Controls
• Communication Network
  • SAE J1939 Data Link
  • SAE J1587 Data Link
  • CAN Bus Termination
• Diagnostics
  • Service Tool Connectors
  • 8-Pin and 9-Pin Deutsch Connectors
• Instrumentation & Outputs
  • Tachometer / Tachograph
  • Warning Lamps (MIL, Stop, Warning)
  • Engine Brake
  • Fan Clutch

File Information

• Manufacturer: Cummins Inc.
• Engine Model: ISLe
• ECM Type: CM850
• Document Type: Wiring Diagram
• Bulletin Number: 4021598 Rev.1
• Language: English
• Format: PDF
• Pages: 1 (large-format schematic)