hardly any assist from elec. motor

I thought i noticed this on mine as well lately, but today i was driving around in electric-only mode without issues, and auto shut downs were happening fine as well, so i assume it was just me being over worried about things. just my 2 cents. I would assume (as i have read) if something was wrong you'd be getting lights on the dash indicating an issue...maybe someone more knowledgeable than me can chime in.

 

It is not clear that there is anything wrong right now.

In fact, things sound just peachy:
* With the new 12V battery, the engine, ICE, should run much less to
turn Motor/Generator1 as a generator to keep the HV battery topped
off it is not being drained through the DC-to-DC inverter to charge the
12V bus and battery.
* Your avatar doesn't say where you are,, but if it's cooler there now
than just a little while ago, the ICE may be running a little more than
you're used to to keep itself and you warm. The "you warm" is
significant. If you run the heater or defrost, no matter how little, the
ICE will run extra, may not shut down at all at stops.
* Running ever so carefully on the ICE alone, taking every advantage of
"no arrow" glides etc, is the most efficient way to go.
* It is far too early to know what effect the new 12V battery is having.
It will take a full tank or more.

As to possible HV battery issues, unless you are getting some warning
lights, or the bars on the Energy Monitor are swinging wildly from
green to red/magenta when you drive or when it sits overnight, nothing
you've said clearly indicates a problem at this time.

Now, let's see what others may think.

 

I can almost garantee you there's nothing wrong as you are not throwing check engine lights. Here's what I would check:

Tire pressure you will probably find they are very under inflated.
A quick cold snap can cause your tires to lose 10 lbs overnight. Or maybe your way behind on maintenance. Oil for motor and cvt fluid.

Or you have lost or begun to lose your inverter coolant pump. See brand new recall notice in "Gen II Main Forum" jdenenburg was nice enough to post. Easy to check your vin on the Toy site. Do you have good coolant flow in the Inverter coolant tank when in "Ready"?

Or its just wicked cold and your car is running to keep its Cats warm.

 

I recently changed my 12 v and experienced a similar issue with the elec motors. I brought car into dealer and was told the 12v connections were not tight enough and something was installed upside down when putting the 12v back together. My advice is to check your 12v. connection.

 

The noise from the wheel well is the pump that transfers the engine coolant in out of the thermos that is located ahead of the left front wheel. The inverter coolant pump is a different item and is located under the inverter. My car is also on the list to need an inverter pump replacement.

 

theclarinetguy32,

+1 on checking tire pressure (every 10 degF drop in air temp =
~1 psi drop in tire pressure) and 12V battery connections, corrosion
where the ground wire connects to the chassis is the usual suspect.

Another probable cause for the lowered MPGs read-outs that you are
seeing is related to replacing your 12V battery.

Unless you attached a separate independent 12V power supply, when
you removed the old 12V battery all your previous mileage and gas use
was erased from whichever CPU keeps it "on file." That means that all
your high warm weather data is lost and your current MPG is being
calculated solely on your recent cold weather data. As a result, you are
seeing much lower readings.

All this to add to the idea that so far at least, from what you've said
there doesn't appear to be a major problem.

 

Just to clarify are you saying that you were 90% of the time seeing the energy monitor similar to that shown in my first attached image and only rarely seeing the energy monitor as per my second attached image?

If I recall correctly I think I most often see the first of these when cruising at highway speeds. Perhaps your Prius just has to re-lean you driving habits a bit before it makes optimum choices of what energy mode to use.

Based on this alone I really doubt that there is anything wrong with your traction battery or electric drive.

 

This sounds like completely normal Prius operation coupled with completely normal human perception. People often "notice" things after a significant event. For example, my cars often drive better after an oil change. From an intellectual standpoint I know that an oil change has no immediate effect on a car's behavior, but my freshly focused attention perceives an apparent improvement, even when there is none. I suspect the OP is experiencing something of this nature.

Tom

 

"A clean car always drives better than a dirty one"

 

Like I said I still don't think there's anything wrong with your car, but that doesn't mean I think it's all in your head.

When you lose your 12V some systems lose their stored data and it takes a while for the systems to re-learn their optimum settings. This can have quite an impact on how the MPG (as displayed on the MFD) is calculated.

Also if you didn't pre-charge the optimo before installing you never know it might have been a bit low (yes even from new there is no guarantee that a battery will arrive fully charged) and that would have made it run in the charging mode more often (as per first attachment in previous post).

BTW. I'm not in North America but I have noticed here and in a few other forums that many there are just starting to feel the impact of colder temperatures and "winter gas" blend on their MPG's right about now.

 

A few clarifications.

There are -four- "coolant pumps". One is belt driven for engine coolant. One is electrical for interior heating from the engine coolant circuit in case the engine shuts down while stopped. One is electrical for pumping engine coolant into and out of the thermos. Finally, there is one in the inverter cooling circuit.

When it's cold out and you have selected "A/C Auto", the system will "demand" heat. If the coolant is below 63C the engine will run. In winter the coolant is below 63C until the engine has been running at least 30 min. So if you are sitting at a light and wondering why the engine doesn't shut down, this may be it! Pearl will shut down the engine at a light, but the heater will be withdrawing heat from it, and after some time (say 10-20 seconds) the engine will start. I haven't seen the effect of the cat cooling off causing this, but I suppose it might be possible.

Just to show how big this effect can be, in the fall, ambient temps around 20C, Pearl was returning fuel economy of 4.4 l/100 km. Today, with ambient temps around -10C the MFD shows 6.3 l/100 km! That's quite a difference. There are other causes in my case, but you get the idea!

I doubt very much there is anything wrong with your car.

 

The engine supplies most of the power at highway speeds. You should see the motor intermittently being used to maintain speed when on a "level" road (minor hills you don't notice plus wind gusts will trigger it when in cruise). If you use the accelerator to increase speed you should see the motor being used to help on the MFD. Unless the traction battery is too hot. Is the fan still working? Vent plugged? Remember, MG2 is only 40 HP and can deliver much less, as it's limited by battery current (to protect the battery). The engine can put out up to 70 HP peak and it has to rev quite a bit to do so.

 

This is fairly normal I think. Unless you noticed a huge difference in power, because when cruising, the engine will normally power the wheels alone, while also sending energy to the battery to keep it at about 75%-80%. Unless you live in a very cold, windy, or cold & windy place, I can't really put my finger on your MPG loss. It could be for a number of reasons. Only a few times have I seen in really cold weather that it won't use stealth mode because the engine is trying to keep warm, it could be that your battery was too hot, or cold, or it could have been carrying out battery equalization. If there are no warning lights, there's no way to diagnose the problem. ):

 

That's the classic Prius specs.
The second generation Prius specifications are 76HP and 82FT-LBS of torque. The electric motor has 67HP and 295FT-LBS of torque. The Prius' computer will only allow it to rev to 5,000RPM, no more.