Why does my Toyota RAV4 Hybrid make a humming noise when parked?

If your Toyota RAV4 Hybrid makes a humming, buzzing, or whirring sound while parked, it is often normal. Hybrids can run electric pumps, fans, and compressors even when the gasoline engine is off.

Common causes include:

• Brake system pump/actuator: A short buzz or hum can happen around startup or when the brake system is building pressure.
• A/C compressor: If the car is in Ready mode or climate control is on, the electric A/C compressor can hum or whine even with the engine off.
• Hybrid battery cooling fan: A fan noise from the rear area can happen when the battery is cooling.
• EVAP system check: Some humming noises can come from an emissions leak-check system that runs after the vehicle is shut off.

What matters most is when the noise happens and where it seems to come from. If the sound is new, very loud, happens constantly, or comes with warning lights, a spongy brake pedal, or grinding, have the vehicle inspected by a Toyota dealer or qualified technician.

Exact operating behavior can vary by model year and conditions, so if you want to pinpoint the source, the owner’s manual or a dealer can help confirm what is normal for your specific RAV4 Hybrid.