Controller displays E12 and the generator will not crank; an emergency stop indicator may be lit.

Safety first: Confirm that it is safe to restart the generator and that no maintenance is being performed by others.

• Check emergency stop button: Locate the red E-stop button on the generator enclosure. If it is pressed in, twist or pull it to release (per label instructions). Verify the E-stop indicator on the controller turns off.
• Inspect remote stop circuit: If a remote stop/start station is installed, ensure its stop switch is not engaged. Check the wiring from the remote station to the generator for shorts to ground.
• Test E-stop switch: With power off, disconnect the E-stop switch leads and test the switch with a multimeter for proper open/closed operation. Replace the emergency stop switch if it remains closed when released.
• Check control wiring: Trace the stop circuit wires in the control panel for pinched insulation or moisture. Repair or replace damaged wiring.
• Clear code and test: After confirming the stop circuit is open (normal), clear E12 and attempt a manual start.