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Discussion Starter #1
I am very happy so far with my new Pacifica. I was amazed at how quiet it was during a demo drive. My vehicle also seems very quiet when running in Electric mode. However, when it switches to Hybrid mode, there is a high pitch whine that seems to vary in frequency all the time. It gets higher in frequency when I'm slowing down, and gets lower in frequency when accelerating. This whine is loud enough to be somewhat annoying and is noticeable even when listening to the radio.

The dealer says this is normal. Could it be the EVT transmission, or something else? Is this normal?
 

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Is it interference coming through the speakers? I've heard that before in our van.
 

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Discussion Starter #3
I sometimes do hear electrical interference in the radio on some AM stations, but that is not what I am noticing. The AM interference is a static like noise that is proportional to my speed, and it is controlled by the volume knob.


The annoying high pitched whine is a pure tone with a varying freqency. It goes higher in frequency when slowing down and goes down in frequency with speeding up, and can vary in frequency even when driving at a constant speed. It is always there when in hybrid mode. It is never there when in electric mode. (I use the Hybrid-Electric app to show which driving mode I'm in.) It has nothing to do with the radio.
 

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Yup, that's the whine/tone that I'm talking about too. Not static on the radio. Even if I have the radio off, I hear the whine/tone. It increases and decreases as you drive the car at different speeds. I didn't clue into the fact that it's only when in hybrid mode, but I'll have to check for me.

The radio reception in the PacHy seems poor compared with other cars, but maybe I shouldn't be surprised with all the electronics in the car. I even took it in to the dealership, they agreed, and then replaced the antenna, but it still didn't help. I mostly notice because it drops the HD radio stations, even in the middle of an open field.
 

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I just talked with the service department at my local Chrysler dealer and they say the whine is from the regenerative braking generator. OK, I guess. However, isn't the regenerative braking in use when driving in the electric mode? So why wouldn't there be the same whine noise when running in electric mode?



It seems to me that something else is going on. I guess I'll just have to get used to the noise. It is not loud, but enough to be somewhat annoying if you have good hearing.


Where is the antenna for the radio? I don't see one anywhere. I think my radio is about average for reception. I haven't checked yet for reception of distant AM stations at night, though. The radio is picking up some noise from the engine when driving and listening to weaker stations. Not surprising with all the computer chips and other electronics in this vehicle.
 

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I just talked with the service department at my local Chrysler dealer and they say the whine is from the regenerative braking generator. OK, I guess. However, isn't the regenerative braking in use when driving in the electric mode? So why wouldn't there be the same whine noise when running in electric mode?
I would agree with them. Sort of..

There are two electric machines in our hybrid. motor A and motor B. Motor A is a smaller 63kW starter/generator. Motor B is the larger 85kW traction motor.

To start the ICE, motor A is powered to rotate the engine and once started the engine uses it like an alternator.

When in hybrid mode the engine does two things. Charges the battery like a generator and your drive is still electric OR allows the engine to apply torque to drive the wheels under high loads

The principle is called Charge Sustain mode and the goal is to sustain your HV battery using the onboard generator, and under mild acceration it compensates for the output by matching the input.. maximum acceleration applys 63kW from the generator, 85kW from the traction motor or full torque from the engine plus the 85kW from the traction motor.

I should also mention that the size of the generator is what makes our Pacifica a good HEV should you decide to never plug it in.. this is not the case with many PHEV's on the market intended for intercity use. These fall apart if you dont charge regularly.

If you havent seen this video by now its worth a browse. 33:10sec in will discuse the powerflow.

 

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I just talked with the service department at my local Chrysler dealer and they say the whine is from the regenerative braking generator. OK, I guess. However, isn't the regenerative braking in use when driving in the electric mode? So why wouldn't there be the same whine noise when running in electric mode?
The ‘regenerative braking generator’ does indeed work in both all-electric and hybrid mode. But it’s only re-charging the HV battery when you are actually braking or, to a lesser extent, when you are coasting and slowing down, or using the selector in ‘L’ to slow the car down.

I’m wondering if you are simply hearing the gas engine running or some component that is turning with the gas engine. Remember that the speed of the gas engine does not necessarily vary according to the throttle position in the PacHy. The computer is constantly adjusting the speed of the engine according to the needs of the vehicle and the charging of the HV battery. The throttle position is simply being interpreted by the computer and has no physical linkage to the engine as far as I know.

I realize that I’m commenting on an old post but apparently the howling idea has been revived. I suppose it’s also possible that some people are just more sensitive or annoyed by the sound than others.
 
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