Cummins 3666268 Signature ISX Wiring Diagram

Electrical faults are much easier to trace with the right diagram in front of you. This is the wiring diagram / electrical schematic document for the Cummins 3666268 Signature ISX.

Document reference: 3666268.

What the diagrams cover

• Electrical circuit diagram for the ISX/Signature engine control system
• ECM connector pinouts and pin labeling
• Sensor signal wiring (crankshaft/camshaft position, intake manifold temperature, oil pressure, barometric pressure)
• Fuel pump and turbocharger actuator wiring
• Chassis connector reference designators and mating views

Models covered

• Signature
• ISX (CM870)

User help

1. Check the fit first. Compare your model and serial number with the coverage shown above. If you are unsure, message us with those details before ordering and we will help you confirm.
2. Get the file. This is a digital PDF download. Nothing is shipped, so you can start using it as soon as you have the file.
3. Open it anywhere. Use any current PDF reader (Adobe Acrobat Reader, your browser, or a phone or tablet app). Save a copy to your computer and to a backup drive.
4. Jump straight to the section you need. Start from the table of contents or search for a part name, fault code or value, then print just those pages for the workshop.
5. Trace circuits methodically. Identify the circuit, connector or harness in the diagram, then check voltage, continuity and grounds at the points shown before replacing components.
6. Safety first. Work on machinery, fuel and electrical systems carries real risk. Follow the document's safety notes, use suitable tools and supports, and comply with local rules. If a job is beyond your experience, use a qualified technician.

Cummins and all model names are trademarks of their respective owners and are used here only to identify compatibility. This store is an independent seller and is not affiliated with or endorsed by Cummins. For informational and maintenance use.