System Operation Description
This procedure is designed to troubleshoot the electrical system when issues are suspected with the injectors or if diagnostic codes related to injectors are frequently active or repeated. The Caterpillar Electronic Technician (Cat ET) is utilized for various diagnostic tests.
Key Tests and Procedures
- Cylinder Cutout Test: Used to diagnose malfunctioning injectors while the engine is running. It helps identify issues by observing changes in fuel position when an injector is deactivated.
- Injector Solenoid Test: Aids in diagnosing open or short circuits when the engine is not running. It briefly activates each solenoid, and a good solenoid produces an audible click.
Troubleshooting Steps
The document outlines a series of detailed test steps for diagnosing injector solenoid problems, including:
- Inspecting electrical connectors and wiring for damage or corrosion.
- Checking for logged diagnostic codes using Cat ET.
- Performing the Cylinder Cutout Test to assess injector performance.
- Executing the Injector Solenoid Test to identify open or short circuits.
- Checking the harness between the ECM and valve cover for open or short circuits.
- Testing the ECM for proper operation by simulating open and short circuits.
Important Safety Note: The electronic unit injector system operates with high voltage (67-73 volts). Always ensure the keyswitch is in the OFF position before performing any electrical tests to avoid severe electrical shock.
For detailed information and specific repair instructions, refer to the relevant Caterpillar service troubleshooting manuals.
