A big drop in mileage!

Roboklotz.

Welcome to PriusChat.

There are very technically knowledgeable folks here who with luck will come
up and help. I'm not one of them, but I will pose a few questions, and your
answers may help them to more quickly identify the problem... if there is one.

* When you say "reserve battery" are you referring to the Battery shown
on the Energy Monitor screen, the one with the wheels, Engine, etc? (If so,
we usually refer to it as the High Voltage battery, HV battery for short.)

* I take it that the evidence of the HV battery not being used to power the
car is lack of yellow arrows from the battery, through the Elec. Motor, and
to the wheels at other than low speeds. At what speed does the change occur?

* It sounds like you are getting repeated cases of green bars. Are you
cycling between blue and green bars? (This would suggest that at least the
12V battery is being recharged via the DC to DC converter and depleting the
HV battery somewhat.)

* Do you have a ScanGauge installed?

* High centering on the snow would seem to be significant. Was there any
discussion with the techs about an HV cable becoming loosened or
disconnected? (If I recall correctly, there is a short run of HV cabling under the
car that is protected only by a plastic cover. Without the HV battery assist the
car would be the equivalent of a Corolla or Matrix and I would guess that 35
MPG would be about right.)

* Did the techs say anything about "trouble codes" being "thrown" or logged?

* Did either of the shops put the car up on a lift for a visual inspection?

Have patience, help is on the way.

 

Hi Robo...,

No expert here. But, you might have them disconnect the 12 V battery and let it sit for 5 minutes, and then reconnect it. This would clear any artificial intelligence adaptation the car has developed. And it should be back to normal after a few days driving then. After doing this the radio programing and windows will have to be reset.

If the problem persists, then there might be something wrong.

My battery will go into the green SOC exiting down a long off ramp, after highway crusing (which the car will charge the batter to highest blue bar during). In colder weather the car will keep the battery at a higher state of charge, as well.

Have them check the cable that runs down in front of the junction between the engine and the transmission. There is a sharp edge on what has been called the "starter hole cover" that the cable might have gotten pushed into. Some of us reverse the plate so that the sharp edge is away from that cable. The Prius does not use a starter, but the engine block casting is common with cars that do. So, there is a hole in the casting to mount a traditional starter. Its covered with a plate. And the plate has tab that sticks out towards the front of the car. The cable runs in front of this tab. Apparently, the tab was meant to hold cable bracket, but it was left out of the final design. By flipping the plate over, the tab can be directed away from the cable. Hobbit has a write-up of this on his technofandom web site.

 

I've experienced that too. Welcome to the extremes of winter. Some of us are trying to enjoy fall still, so no more reminders of what's to come...

Anywho, if there are no codes and the engine is running fine, just drive it.

I can recall a holiday drive where in both directions the Multi-Display showed green the entire time. That was quite unexpected. And there are numerous horrible heavy winter commutes home where I was seeing pink and with only a few short MPG bars most of the way out of the cities. All that is normal. When you get home, you'll confirm that with the change back to what you expect to see.

.

 

donee,

Well done! I had forgotten about that irksome little detail.

 

Two words ... weather and temperature. If there were no codes, don't worry about it.

 

Cold weather will do that. The Prius has to run the ICE more to make heat. As long as the engine is running, that power is used to move the car and charge the battery. In winter we often see green bars.

Tom

 

roboklotz, sounds like you are a prime candidate for grill blocking and the EBH. Are your tires still at the desired pressure? If you've got the defrosters & the heat on all the time you'll take a FE hit. If there isn't any physical damage and there aren't any stored codes then all I can say is "Welcome to Winter."

 

I noticed a sharp drop in FE when filling with 10% ethanol

 

A couple of weeks ago, Seattle got a ton of snow. I drove my Prius through it including some high centering of snow and ice. After the snow melted, my car was dragging something and I took it in. The plastic cover over the high voltage cables was torn off exposing the cable. My cable didn't get unplagged, but that could explain your problems.