Generator shuts down, controller displays E-07

Safety: Disable automatic start and isolate AC output. Overspeed can cause severe mechanical damage; do not repeatedly restart until the cause is identified.

• Inspect engine speed sensor: Locate the speed sensor at the flywheel housing. Check for loose mounting, damaged cable, or oil contamination. Clean the sensor tip and ensure correct gap per CAT specifications.
• Check wiring harness: Follow the speed sensor harness to the controller. Look for chafed insulation, crushed sections, or loose connectors. Repair or replace damaged sections.
• Throttle/fuel rack inspection: On mechanical fuel systems, verify that the fuel rack or throttle linkage moves freely and returns to idle. Lubricate pivot points lightly if sticking.
• Controller configuration: Confirm that the controller is set for the correct engine speed (50/60 Hz) and number of flywheel teeth if configurable. Incorrect settings can misinterpret speed.
• Clear code and test: Clear E-07 and perform a no-load test run while monitoring engine speed on the controller. Stop immediately if speed rises abnormally.

If overspeed recurs, do not continue to run the unit. A CAT technician should verify governor operation and controller calibration.