Controller displays E09 and the generator will not start in AUTO mode, even during a utility power outage.

Safety first: Turn OFF the generator and lock out the ATS if possible. Only qualified persons should open the ATS cabinet due to live utility connections.

• Check low-voltage control cable: Inspect the multi-conductor control cable between the Firman standby generator and the ATS. Look for physical damage, crushed sections, or rodent chewing. Repair or replace damaged cable.
• Verify terminal connections: With power isolated where possible, tighten all low-voltage control terminals at both the generator control board and the ATS control block. Loose screws can cause intermittent E09 errors.
• Inspect ATS position switches: Many ATS units use micro-switches to indicate NORMAL or EMERGENCY position. Check that the actuator cams are engaging the switches and that the switch wiring is intact.
• Confirm wiring per Firman diagram: Compare the installed wiring to the Firman ATS wiring schematic for your model. Correct any mis-landed wires.

If E09 persists, the ATS control board or the generator controller may require professional testing and possible replacement.