Generator will not start, control panel shows E01 immediately after start attempt

Safety first: Turn the generator to OFF, isolate the ATS (Automatic Transfer Switch) so the load is not connected, and disconnect the battery negative terminal before working on the engine. Allow the unit to cool fully.

• Check oil level: Remove the dipstick on the Hyundai Power Products standby generator engine. Wipe, reinsert fully, and check level. Top up with the manufacturer-specified engine oil (typically 10W-30 or as per data plate) to the FULL mark. Do not overfill.
• Inspect for oil leaks: Look around the oil filter, sump gasket, drain plug, and oil cooler (if fitted) for fresh oil. Repair any obvious leaks before restarting.
• Reset and test: Reconnect the battery, clear the E01 code using the control panel (refer to the Hyundai controller menu), then attempt a manual start. Observe the oil pressure warning lamp or icon.
• Check oil pressure switch: Locate the oil pressure switch on the engine block (usually near the oil filter on Hyundai-branded engines). Inspect the connector for corrosion or loose fit. Clean contacts and reseat. If you have a multimeter, verify continuity changes when cranking (refer to service manual values).
• If E01 persists: Replace the oil pressure switch with a Hyundai-compatible part. If the engine still shuts down on E01 despite correct oil level and a new switch, do not continue to run the unit—contact a qualified Hyundai Power Products service technician to check actual oil pressure with a mechanical gauge and inspect the oil pump.