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450h - Odd noise when starting the engine and backing up

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Old 08-26-20, 08:48 AM
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noci20
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Default 450h - Odd noise when starting the engine and backing up

Hello,

I have had my newly purchased 2020 Lexus RX 450h now for about 3 weeks. It had only 5 miles when I picked it up from the dealership. After the first few days, I started hearing a noise whenever I started the engine that continues as I back-up (reverse) and then it disappears. It is pretty loud (audible). Sounds as though a loud motor or a fan getting turned on. People outside the vehicle can clearly hear it and that is how I came to know as I have had the windows up most of the time. I am taking it to the dealer for them to diagnose the issue. Any thing I need to know before going into the dealership for a check up?

TIA.
Old 08-26-20, 09:04 AM
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AndrewTO
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Does it sound like this?


If it does, it's actually a built-in sound. Since most hybrids run on battery power in low speeds, they may present a danger (according to the gov't anyways) to surrounding pedestrians, cyclists and/or blind people because they can't hear your vehicle coming. Therefore, a sound is emitted outside of the vehicle to let them know you're there.

I believe in the U.S. that all electric vehicles including hybrids will be mandated to emit a sound up to a certain speed by next month, hence why older hybrids/electric vehicles may not have this "feature."
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Old 08-26-20, 12:06 PM
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ericsan13
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Originally Posted by AndrewTO
Does it sound like this?
My neighbor's RAV4 makes this noise and I can tell every time they leave their home. It's much louder than a gas car and not a pleasant sound.

Thankfully my hybrid does not make this noise! Just a mechanical whirring noise for 1-2 seconds when you shift into reverse and then blissful silence.
Old 08-26-20, 04:16 PM
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noci20
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Thanks AndrewTo. Yes, exactly the same noise. The dealer said the same thing as well - nothing to worry.

Agree with Eric, it isn't a pleasant noise.
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Old 08-28-20, 09:52 AM
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ericsan13
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Originally Posted by noci20
Thanks AndrewTo. Yes, exactly the same noise. The dealer said the same thing as well - nothing to worry.

Agree with Eric, it isn't a pleasant noise.
Perhaps you can disconnect the speaker or hack it to play snake jazz? Is it as obnoxious when you're inside the car?
Old 08-28-20, 03:34 PM
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The Pedestrian Warning signal is louder in reverse than forward...speaker is in
the front and apparently the pre-2019 volume was not heard. Perhaps they should
have provided a second speaker at the rear?

Notice it is loudest when you first step off the brake and diminishes slightly as you roll?
Changes pitch slightly as you go faster. Shuts off when fully stopped and when the
IC engine is providing conventional noise.
Old 09-19-20, 08:53 AM
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Hot off the Presses:
new 2021 Lexus "Acoustic Vehicle Alerting System on ES300h has been updated
with a speaker behind both the front grille as well as at the rear of the vehicle"

Looks as if Corporate reads Club Lexus!
Old 11-01-20, 09:59 PM
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x52
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You could either muffle the speaker or disconnect it. It is located in front of the radiator. If you disconnect it, there will be a warning. To trick the car in thinking there's a speaker, connect a 4ohm 5% resistor, such as https://www.amazon.com/dp/B076W8CW9W/ with these plugs https://www.amazon.com/dp/B075MVP6MK/ and secure it with shrink tube or electrical tape. You will have to shave the plugs so it can fit. Enjoy near silence (you can still hear the electric motor).
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Old 01-30-24, 03:39 PM
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AZJowett
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Originally Posted by x52
You could either muffle the speaker or disconnect it. It is located in front of the radiator. If you disconnect it, there will be a warning. To trick the car in thinking there's a speaker, connect a 4ohm 5% resistor, such as https://www.amazon.com/dp/B076W8CW9W/ with these plugs https://www.amazon.com/dp/B075MVP6MK/ and secure it with shrink tube or electrical tape. You will have to shave the plugs so it can fit. Enjoy near silence (you can still hear the electric motor).
This worked perfectly. My wife could hear me come into the garage from the other side of the house.

Last edited by AZJowett; 01-30-24 at 05:16 PM.
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