Generator shuts down and displays E06; engine speed appears too high or too low before shutdown.

Safety first: Turn OFF the generator, disconnect the battery negative terminal, and ensure the unit cannot auto-start.

• Inspect governor linkage: Locate the mechanical governor arm and linkage between the engine and the carburetor or injection pump. Check for binding, rust, or debris. Lubricate pivot points lightly and ensure the return springs are intact.
• Check throttle plate movement: Manually move the throttle lever at the carburetor/injection pump to confirm smooth travel from idle to full. Correct any obstructions or bent linkage.
• Inspect speed sensor: On many Firman standby units, a magnetic pickup sensor is mounted near the flywheel or ring gear. Check the sensor tip gap (usually 0.5–1.0 mm) and clean off any metal shavings. Ensure the connector is tight and the wiring is not damaged.
• Reset controller: After mechanical checks, reconnect the battery, clear the E06 code, and start the generator while monitoring RPM or frequency (which should be ~60 Hz). If the speed still hunts or trips, the electronic governor module may be faulty.

Governor calibration and module replacement are best performed by a qualified technician with access to Firman service procedures.