Battery constantly pulling towards wheels while in drive & idle

Have you checked the fluid levels? Are your sure the coolant is full? I doubt you have a issue with the traction battery at this point.

Are you certain the Prius is in S4 mode when you are parked as you described?

 

the 'creep' feature would use the battery as you pull into the garage. the battery itself doesn't make any noise, so i assume you are hearing the tranny. how are your tyres pressure?

 

When you "pulsating noise", are you referring to the fan for the traction battery?

Also, the arrows you describe they are on when you are in Park. Is that correct? Are looking at the Energy/battery screen on the MFD or the HID screen on the dash by the odometer?

 

I'm going with...you haven't got this problem as figured out as you think.

I have to agree, that as a chemistry based component, I don't think what you are hearing is the battery slowly pulsating.

My FIRST exploration would be into why your ABS light is on.
It might not just be a faulty sensor.

But I'm placing my purely speculative bets on it's NOT your Hybrid Battery.

If I'm wrong?
The good news is your still under warranty.

 

The noise you hear could be related to the ABS light indicating something is wrong with the brakes. As you probably know, the car will creep even with a light application of the brakes. A harder push on the brake pedal will stop the creep and the flow of current from the battery. If the issue is with the brakes, it is possible that shutoff isn't occurring and you're hearing a noise from the drive motor. I'd suggest getting the codes to see what the diagnostics are telling you.

 

I think you are worrying about nothing. MPG varies just like everything else. The noise you describe is normal and will always do that if you are in gear and the transaxle is being driven only by the battery. It is also normal for the noise to stop when you go into Park.

S4 mode is described as follows. For more information on all of the modes, refer to this link.

http://techno-fandom.org/~hobbit/cars/five-stages.txt

S4:
Stage 4 is normal, full hybrid operation. The Prius is most efficient
in S4. The car will go into golf-cart mode at the computer's
discretion. You can encourage it to do so by lifting your foot off the
accelerator pedal for a moment, and then pressing on the pedal very
lightly. This is known as "feathering" the pedal. Feathering does not
force the car into golf-cart mode, nor is it necessary for the car to
go into golf-cart mode. It merely encourages the car to do so a little
bit sooner than it would otherwise do on its own. The benefit of
feathering the pedal is questionable, since the computer is deciding
when it thinks Golf-Cart Mode is most desirable. Increasing the time
spent in Golf-Cart Mode may only increase the efficiency losses
involved in charging the battery and drawing power from it. On the
other hand, encouraging Golf-Cart Mode when the SOC is very high may
be useful, as it creates head room in the battery to accept charge
wheen needed.
Above 42 mph the ICE must spin, and will generally provide power. It
is possible for the ICE to spin without providing power to the car
above 42 mph, and this has been observed. But since the ICE is more
efficient at these higher speeds, Golf-Cart Mode above 42 mph (Super
Golf-Cart Mode) is unusual. So the maximum speed in EV Mode is 34 mph,
cutting out at a tiny fraction over 34 mph, and the maximum common
speed in golf-cart mode is 42 mph. You can go faster in non-EV
golf-cart mode than you can in EV mode.

I will echo what was said above, if you do have a problem with your traction battery, it is covered under warranty.

Concentrate on getting the ABS problem solved, then go from there.

Best of luck to you.

 

the robot noise is the 'vehicle proximity notification system'. to warn pedestrians, that a car is approaching which may be otherwise nearly silent.

new tyres may account for your mpg drop.

 

exactly, no problems there...

EDIT: Additional info.

The OP did mention new tires. All of the seasoned regulars here on Prius Chat are aware that MPG can change when new tires are thrown in the mix. I suspect that could be one of the items contributing to the loss of three MPG which is being claimed by the OP.

End of EDIT.

 

1) it depends on what tires you mount.

2) if you mount low rolling resistance tyres, it takes a few thousand miles to break them in, and it depends on how they compare to the tyres you had.

3) worn tyres actually give the best mpg, worse everything else. there's no friction.

 

The pulsating sounds like the robot pedestrian warning bisco was talking about to me also, but that should not be going if you are stopped, even in D. When you let off the brake pedal it resumes. Nor should the energy monitor show any arrows when you are in D but stopped. It's almost like you aren't holding the brake down hard enough and the car thinks it is in creep forward mode. Or maybe the tire shop messed up the brakes to where they aren't holding the car correctly?

 

Dead on. It sounds like EV is active and you are stopping the car with the brakes. That can't be good for the electric motors. The proximity indicator and the arrows on your screen verify this diagnosis. The computer does not know you have come to a complete stop. Take the car to the dealer, as soon as you can.

 

So the tire shop or someone/something else broke the ABS sensor wire. That's going to cost (new sensor). About $100 last I checked.
You -must- get that fixed ASAP! By law and for obvious reasons (the braking system doesn't work properly without it).
As posted above, that is the problem you have to fix. Find a good Toyota dealer to do it. It's not a simple job due to the hybrid complexity.

 

It is a simple job, as mechanical repairs go.

Those sensors are also used by the VSC system, and that is why the cruise won't work. It is being told you are skidding and cancels.

The brakes do still work, but in low tech mode. This is for safety. In other words, they can still stop you, but if you approach skidding braking intensity you would find the car spinning. A very experienced driver can compensate, others not so much. Once repaired you will be amazed by how hard the Prius can stop (remove all loose items from the cabin if you decide to test this!!).