Cummins Signature & ISX CM870 Wiring Diagram (3666268)

Wiring diagram 3666268 covers the Cummins Signature and ISX with the CM870 control module, the EGR engines used in Class 8 trucks.

It shows the engine control system circuit diagram, ECM connector pinouts with pin labels, sensor wiring (crankshaft and camshaft position, intake manifold temperature, oil pressure and barometric pressure), fuel pump and turbocharger actuator wiring, and chassis connector designators with mating views.

What the diagrams show

• Engine control system circuit diagram
• ECM connector pinouts and pin labels
• Sensor wiring: crankshaft and camshaft position, intake manifold temperature, oil pressure, barometric pressure
• Fuel pump and turbocharger actuator wiring
• Chassis connector designators and mating views

Compatibility

• Models: Signature with CM870, ISX with CM870
• Control module: CM870
• Part number: 3666268
• Application: Class 8 on-highway trucks
• Document type: Wiring diagram

Before you buy

Later ISX engines with the CM871 or CM2250 controller are wired differently and need their own diagrams. Check your ECM before ordering.

Your engine's dataplate shows the engine model, the engine serial number (ESN) and the CPL number. Compare those with the models above. If you're not sure, email us the dataplate details and we'll check for you.

File format

Digital download, delivered as a ZIP file. Unzip it before opening. Opens on a computer, tablet or phone.

We're an independent seller and are not affiliated with or endorsed by Cummins. Brand and model names are used only to identify the engines this manual covers.