RAV4 plug in hybrid 2021. Fog horn noise in ev mode

[mjh18]

Hi All,

Has anyone else has an issue when setting off in EV mode, the car makes a fog horn sound coming from front drivers side, it only lasts a few seconds and then goes off. I have had the car now for about 3 months ( the car is 9 months old ) and it has made this noise about 6 times in total. I have taken it back to dealer but they state that they cannot replicate the noise but have checked electrics and all appears ok. 
 

regards

 

mjh18

[Catlover]

Is this not the legally required sound to warn pedestrians of the car present and moving in on the,pm, rather then them having to jump out of the way.

[Bcc212]

This is likely the heat pump noise. Well documents on rav4world 

https://www.rav4world.com/threads/heat-pump-noise-on-prime.309810/

Apparently there is a fix!

[Broadway One]

Hi all....pleased to read this posting, I'm experiencing similar.

Wasn't there initially but has developed in the past month.

Just 3 months in & 1000mls covered.

Great link relating to lower temperatures suggesting likely cause.

Cold start, EV mode, 2/3 degrees, groaning noise lasting 20/30 secs. on moving off.

All relevant in my case.

Barry Wright, Lancashire.

 

 

  

 

 

 

[ernieb]

I've assumed it's the heat pump and found that it can also vary with road speed, only sounds bad when it's very cold and last only short time.  That heat pump switches into a different mode when it's very cold to extract whatever it can from the air.  The Youtube 'Car Nut Channel' guy gives a very good explanation on how it works in two videos.

 

[Nick72]

To be honest mine makes all kinds of industrial noises. It's like something from a 70s power station.

[Nick72]

Or, thinking about it, a submarine. 

[ernieb]

1 hour ago, Nick72 said:

Or, thinking about it, a submarine. 

It’s certainly an interesting combination of sounds and clunks I don’t give it a second thought now.

[Nick72]

2 hours ago, ernieb said:

It’s certainly an interesting combination of sounds and clunks I don’t give it a second thought now.

Yeh it doesn't bother me. The whole car is industrial. But to be honest I like it that way. It's a masterpiece of industrial engineering. 

[Broadway One]

 

19 hours ago, ernieb said:

It’s certainly an interesting combination of sounds and clunks I don’t give it a second thought now.

Hi all....as a retired engineer I find the sounds of a machine doing it's stuff reassuring.

However the 2 video postings of how complicated HVAC systems are spooks me.

So much kit fitted on the platform.

My remedy, just ignore & enjoy the drive.

Barry Wright, Lancashire.

PS Fingers crossed Toyota main dealers are up to speed with the technology 😕 😕

   

[ernieb]

Barry, it would worry me if there was a problem in the HVAC system in the UK where generally they just re gas or change the unit out for a new one.

[Devon Aygo]

Could it be:

BE-00612T-TME

 

Subject: "Train horn noise" from A/C compressor when the vehicle is started.

 

Description of the phenomenon: Some customers may experience and report the abnormal noise, "train horn noise", immediately after the start of vehicle and air conditioner(A/C) system under cold ambient temperature (Approx. 5°C or less). This noise is caused by pulsation noise due to compression of liquid refrigerant in A/C compressor, and easier to occur at low temperatures. Tens of seconds after the occurrence, this noise will be disappeared.

 

Production change :

The following has been changed:

• The logic of A/C ECU (AMPLIFIER ASSY , AIR CONDITIONER) was modified to improve condition of liquid compression in A/C compressor.

 

Repair Procedure: - Reprogramming

For improve the above phenomenon, reprogram the "A/C ECU" to the new available calibration ID

[Nick72]

I want it. How do I get it?

I'd also like some escaping gas sounds and banging pipe sounds too. All adds to the industrial feel authenticity. 

Perhaps some whining turbo machinery would be nice too.