Generator cranks but does not start, controller shows E-02

Safety: Disable automatic start, isolate AC output, and keep ignition sources away from fuel. Wear eye protection and gloves.

• Verify fuel level: Check the diesel or gas supply tank gauge. For diesel CAT standby units, ensure fuel level is above the pickup tube minimum (often 1/4–1/3 tank). Refill if low.
• Inspect fuel shutoff valves: Confirm all manual fuel shutoff valves between tank and generator are fully open.
• Replace primary fuel filter: Locate the primary fuel filter/water separator on the engine side. Close upstream valve, remove the filter, drain into a safe container, and install a new CAT-compatible fuel filter prefilled with clean fuel. Bleed air per the engine manual.
• Check electric fuel lift pump: With battery connected and key in RUN (no crank), listen for the fuel pump hum. If silent, check the fuel pump fuse and relay in the control panel. Replace blown fuse only after inspecting for shorts.
• Bleed air from system: On diesel models, use the manual priming pump or bleed screws on the fuel filter housing and injection pump until fuel flows without bubbles.
• Attempt restart: Clear the E-02 code and attempt a manual start. Observe fuel pressure reading if available on the controller.

If fuel pressure remains low or the engine still will not start, the fuel lift pump or injection system may require professional service.