humming sound when plugging in J1772 - NOT charging

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fromport

Well-known member
Joined
Dec 27, 2012
Messages
606
One of my rav4ev's (the one I am keeping) recently started new behaviour.

When I return home, my (open)EVSE is in sleep mode. (timer enables it after 10 pm for cheep electricity ToU)
I plugin the J1772 plug: both LED's stay off, don't even blink once.
Immediately the humming sound of a coolant pump starts: what it normally would do if the onboard charger _is_ running (which it isn't) to cool it.
I checked after an hour and sound was still there.
This morning, after charging to "normal" after a couple of hours it started doing the same (J1772 was still plugged in, openevse was sleeping on timer)

When i plug in the J1772 in my other rav4ev, it stays silent

Power cycling the 12 volt battery didn't help: same result.

I even checked with the supplied trickle charger:
Just plugging the J1772 connector in and the humming starts
https://www.youtube.com/watch?v=xW1oTlviyJI
When i plug in the J1772 in my other rav4ev, it stays silent
https://www.youtube.com/watch?v=e-zYtQ8LIY0

I measured voltages on the 12 volt batteries:
The one with the humming sound has 13.04 volt (charged at night)
The one not making the humming sound 12.4 volt

Any ideas before I make a trip to the dealer ?
 
TonyWilliams said:
I thought the humming was normal.

I don't get it.
the car is not charging, so no need to cool the built-in charger.
So why is the cooling pump running ?

It will use power from the 12 volt battery, and last time I checked, for hours and hours.
I will try and measure how much current is being drawn when the pump is running.

one rav4ev shows this behaviour, my other one doesn't.
Isn't that weird ?

*update*
Tony, the humming itself is not ab-normal.
The fact that is hums when it is not charging is what bothers me
 
When plugged in and on timed charging, my car make a whining chirp, the pump comes on for a moment, then the lights above the charge port start alternately blinking. Then everything goes quiet and there's just the blinking. I use the Leviton EVB40 EVSE with the RAV, so the EVSE is always ready to charge, just the car is delaying. I don't know if that's the same or different from your situation.
 
miimura said:
When plugged in and on timed charging, my car make a whining chirp, the pump comes on for a moment, then the lights above the charge port start alternately blinking. Then everything goes quiet and there's just the blinking. I use the Leviton EVB40 EVSE with the RAV, so the EVSE is always ready to charge, just the car is delaying. I don't know if that's the same or different from your situation.

Both my rav4's are not on a timer: direct charge when plugged in.

It just happens to this one rav4ev, and just when you plug in a J1772 plug.
In the youtube movie I am using the supplied trickle charger and the wall plug is in my hand, not even plugged in, so there is no signal
apart from the resistor in the plug itself that the rav4ev can detect.
 
fromport said:
One of my rav4ev's (the one I am keeping) recently started new behaviour.

When I return home, my (open)EVSE is in sleep mode. (timer enables it after 10 pm for cheep electricity ToU)
I plugin the J1772 plug: both LED's stay off, don't even blink once.
Immediately the humming sound of a coolant pump starts: what it normally would do if the onboard charger _is_ running (which it isn't) to cool it.
I checked after an hour and sound was still there.
This morning, after charging to "normal" after a couple of hours it started doing the same (J1772 was still plugged in, openevse was sleeping on timer)
I've seen this before with mine. It's pretty rare. Can't remember when the last time it was doing this. But it has and I won't be surprised the next time it does it again. I think I remember somebody saying it will do this to remove humidity or something similar. Sounded odd but it did eventually stop doing it and, again, it's very rare. (Couple times a year, maybe?)

I don't think you should worry about it. Give it a few weeks anyway.
 
miimura said:
Incredulocious said:
I don't think you should worry about it. Give it a few weeks anyway.
I agree. As long as the car charges normally, don't worry about it.

thanks both for your feedback.
It is just weird that one of them is showing this behaviour and the other one isn't.
The one that hums is the one I drove in the rain the last few days, so it is very well possible that it could be humidity related
I just wonder: what would running a pump do for removing humidity ?
Especially as the charger is not enabled.
And again: just plugging in a J1772 plug triggers it, totally not connected to pilot signal or anything else.

WIll keep an eye on it for a few weeks like you suggested and see if it stops.

Thanks again!
 
Here's the thread I remembered (and that I participated in because I was hearing the noise too) and that brought up the moisture/humidity control notion:

http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=146&p=12156&hilit=humidity+moisture

And I know that this part of the thread is discussing the noises while charging (as opposed to just plugged in) but I know I've heard it do it a number of times while plugged in and it's waiting for a later, scheduled charge.
 
TonyWilliams said:
Running the a/c dries the air.
It is not the AC, that is a deeper growl.
This is a pump for the cooling of the charger
The same pump that at lower amps doesn't run continuously but intermits
 
Incredulocious said:
Here's the thread I remembered (and that I participated in because I was hearing the noise too) and that brought up the moisture/humidity control notion:

http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=146&p=12156&hilit=humidity+moisture

And I know that this part of the thread is discussing the noises while charging (as opposed to just plugged in) but I know I've heard it do it a number of times while plugged in and it's waiting for a later, scheduled charge.

thanks for the link!
last posting " now it's buzzing when it is not charging (JuiceBox not indicating power draw)"

Same behaviour

I happen to have a spare J1772 cable (ordered two cables from Tony recently for new openevse builds) and even with nothing attached to that cable it starts to hum.

The pump will run for hours, draining the 12 volt battery
That is my biggest concern at the moment

Will report in a few weeks if/when it stopped

thanks all
 
My car has definitely made this noise, but I don't recall the last time. My car is on a timer.

I suspect you've hit some threshold for battery temp.

When it makes the noise, does the main contactor close? If so, put your hand directly on the Zero-Stat battery heater on the backside of the motor "stack", passenger side, and see if it heats up.

If the main contactors do not close, find exactly which pump is running. Putting your hand on hoses around the battery heater should quickly find it (there's not that many parts under the hood!). The pump at the front of the motor assembly is for the cabin heater, so it shouldn't be that one. It will be behind, near the battery heater.

Let's identify what is actually happening first.
 
TonyWilliams said:
My car has definitely made this noise, but I don't recall the last time. My car is on a timer.
I suspect you've hit some threshold for battery temp.
yesterday I emptied about 59% of the normal battery charge.
This night I limited my charging amps to 10 amps, making the charge process _long_
Charging started 22:05 until 5:30am.
This morning I check at 6:30am: car full and quiet.

I walked my dog and when I got back around 7:30am (evse still enabled (till 7:55am) the rav4 was humming.
Neither of the 2 leds were on, so the evse relay was NOT enabled, neither was the contactor of the rav4
It was about 58F at 6:30 and warmer (sun was out) around 7:30 when I returned.
Car is parked in car port, so no sun on the rav4 itself.


When it makes the noise, does the main contactor close?
no
_nothing_ is activated
no leds are on on the rear left side
no relay in the openevse is activated

Even when i use just a cable , nothing connected to the other end of the cable and just plug the J1772 part in, the pump starts to run.
The proximity pin resistor seems to trigger this behaviour.


If so, put your hand directly on the Zero-Stat battery heater on the backside of the motor "stack", passenger side, and see if it heats up.
that heater runs of the HV DC i assume ? so the contactor needs to be to activate the heater, right ?
I am 100% sure the contactor is off.

If the main contactors do not close, find exactly which pump is running. Putting your hand on hoses around the battery heater should quickly find it (there's not that many parts under the hood!). The pump at the front of the motor assembly is for the cabin heater, so it shouldn't be that one. It will be behind, near the battery heater.

The sound of the pump that is running comes from the middle front of the battery pack under the rav

Let's identify what is actually happening first.
 
fromport said:
The sound of the pump that is running comes from the middle front of the battery pack under the rav

That pump is the battery and high-voltage component 12 volt powered coolant pump (the G48 fluid), so clearly the proximity pin is signaling the car to start circulating coolant. This, by the way, is exactly the way it works on the Tesla Roadster.

Is there any chance these two vehicles have different firmware?
 
TonyWilliams said:
That pump is the battery and high-voltage component 12 volt powered coolant pump (the G48 fluid), so clearly the proximity pin is signaling the car to start circulating coolant. This, by the way, is exactly the way it works on the Tesla Roadster.
Is there any chance these two vehicles have different firmware?

They both had the firmware update, so I _assume_ they are running the same firmware.
Not all dealers install a sticker under the hood with firmware version number :-(

But this is the latest service memo I could find

warranty-service-2015-3.png


I think that makes both rav4's have the same software.
The other one has been in for service afterwards.
Is there any more recent firmware that became available after the safety recall update ?
 
TonyWilliams said:
1-3-101 is the newest firmware. It should be on a sticker under your hood.

I asked for it twice at he DCH of oxnard dealership.
They claimed they don't have the stickers and thus don't need to put one under the hood.

I have more negative than positive experiences with this particular dealership regarding rav4ev
 
Is there any way to check firmware version without taking the vehicle to the dealership?
 
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