Cummins QSB6.7, ISC, QSC8.3, ISL, ISLe3 & ISLe4 Electronic Control System Troubleshooting and Repair Manual

When one of these engines logs a fault code or has an electrical problem, this is the manual you work from. It covers the electronic control system on the QSB6.7, ISC, QSC8.3, ISL, ISLe3 and ISLe4.

You look up the fault code, or the symptom if no code is set, and follow the checks for that circuit. It includes ECM pinouts, sensor circuits, diagnostic steps for the fuel system, sensors and actuators, component tests, and how to repair wiring and connectors.

What the manual covers

• Fault code diagnosis and symptom-based troubleshooting
• ECM pinouts and sensor circuits
• Fuel system, sensor and actuator diagnostics
• Wiring and connector repair
• Component testing

Compatibility

• Models: QSB6.7, ISC, QSC8.3, ISL, ISLe3, ISLe4
• Engine families: B-series (QSB6.7), C-series (ISC, QSC8.3), L-series (ISL, ISLe3, ISLe4)
• Manual type: Electronic control system troubleshooting and repair

Before you buy

This is the electrical side only. Mechanical repairs such as pistons, liners or the cylinder head are in the Troubleshooting and Repair Manual, Bulletin 4021418.

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.