Generator display shows E15 and the unit shuts down intermittently.

Safety first: Turn OFF the generator and disconnect the battery negative cable.

• Locate IAT sensor: The IAT sensor is typically mounted in the air intake duct or air filter housing. Refer to your Yamaha service manual for exact location.
• Inspect connector: Disconnect the sensor and check for corrosion, bent pins, or moisture. Clean and dry as needed.
• Test sensor resistance: Measure resistance across the sensor terminals and compare to Yamaha temperature/resistance chart. Replace the sensor if readings are out of range.
• Check wiring harness: Trace the harness back to the control board, looking for chafing or breaks. Repair any damaged wires.
• Clear code and test: After replacing or repairing, clear E15 and run the generator to verify stable operation.