Humming noise
8 Answers
Do you have the LED headlight package offered on that vehicle?
Sorry I hit submit too soon. Are you hearing this after the car has been parked and shut off for a few hours? Or is this while the car is running?
Cooling fan running? Should turn off after a couple of minutes.
Fans would still kick on in accessory mode if ac is on. After about 4 hours since the motor is shut off and the computers are in sleep mode if the battery voltage is above 12.5v and ambient temp is above 40 degrees the computer runs an EVAP self test. The pump kicks on pressurizes the system and performs a leak check. If the test fails it runs a second test immediately after. If it fails again when the car is started the check engine light will be on. Very possible that the sound you’re hearing is the pump running. When you turned the car on it aborted the test this test/noise is a normal function and condition
This occurred after the car had been sitting for awhile. Also, since the Subaru dealer could not give me an answer, when we go away for 2 months, our 2017 legacy’s battery is always dead when we return. My 2012 vw starts right up. Thanks in advance.
I’m pretty sure it’s the EVAP self test is what you’re hearing but at times the cooling fans for the led lights kick on but usually only when the lights are warm after being on a while
When you let the car sit for extended periods of time it’s a good idea to disconnect the negative battery cable. Also if you leave the key fob within 8 feet from the car it will send a signal to the keyless access module every 45-60 seconds thus not allowing the computers to go into sleep mode. This causes excessive battery drain. There is a ECM update to improve battery life that the dealer will do free if you’re under the original 3 year 36,000 mile warranty.
