Turning on and off defrost turns on heater

[Gutsy]

Hello,

I searched to see if anyone brought this up on any of the posts here and couldn't find one. I have a 2008 package 6. When I press the defrost switch on my steering wheel to momentarily clear the windshield, and then turn it off, the heater turns on still stays on. This happens when the heater is off to begin with.

I then have to click on the climate button on the MFD and turn the heater off all the time.

Is there a way to program the system to turn the defroster "off and on" .. without it automatically turning on the heater?

Thanks in advance!
Dave

[qbee42]

The Prius is designed with automatic climate control. In normal use you set a temperature and then forget about it. If you are cold, bump up the setting. If you are warm, lower the temperature setting. You can do it right from the steering wheel. Trying to manually override the automatic system just makes a lot of work for you. Even on manual, the temperature setpoint is used to determine heat output.

If you insist, you can use the Auto A/C button on the steering wheel to cancel automatic mode. I don't know of any way to change the default behavior when switching to defrost. There may be a way, but not to my knowledge.

Tom

[effwitt]

I noticed the same thing on my 2007 yesterday. I started with the heater off to get the engine temp up as fast as possible, turned on the defroster for 30 seconds or so and when I got to a red light a bit later noticed that the fan was running.

Seeing how fast the heater can lower the water temp was a real eye-opener - even more than seeing how much current is generated under modest braking while at highway speeds.

[Gutsy]

Thanks Tom .. your suggestion to turn off the heater by pressing the AC button on the steering wheel worked! Just wished I didn't wish I had to always take that extra step to press the button ... but I can live with that!

Thanks!
Dave

[jpadc]

This is a major pet peeve of mine about the car. I have brought it up here on the forum before (with little to no empathy from others). Glad to know it bothers someone else as well.

Its most bothersome now during the winter with my very short commute. I hate having to deal with the car going into Auto A/C whenever I need a few seconds of defrosting.

The only alternative is to start the defrost and then turn the Auto A/C off in the climate control screen of the MFD. However, with the defrost left on (even at a low hear setting) that still results in the ICE running at stop lights till it warms up (which given my short drive will never occur). So I'm left with having to hit two buttons on the steering wheel (one on each side just to increase the pain) to turn the defrost (and the heater) back off.

An annoyance... some might say befitting the driver

[qbee42]

That's why I gave up fighting the car. I tried that sort of approach when my Prius was new, and soon realized that it's easier to let it do its thing. The only climate buttons I use are the ones setting the temperature and the defrost button. Otherwise I leave everything on automatic.

I know it should be easier, but it isn't. From my perspective the small potential gain isn't worth the effort.

Tom

[donee]

Hi All,

I have been using this "feature" to get the engine down to about 85C, when it gets up to 90C in my drive home. As I have a 90 % grill block on the car right now. In the morning, its 15 F and its just not a problem. But some of the evening commute temps are up to 35 F lately. So, with the add-on temp gauge I know when to trigger the heater that way without taking my eyes off the road. Then when I roll into a stop, I do the Climate/Off buttons.

[KMO]

I think this may be one of the dealer-settable options. There are a number of such settings, such as "is the A/C enable turned on when you press the AUTO A/C button (default yes)".

Ah, found a copy of the relevant page: http://andrew.daviel.org/prius/m_01_0030.pdf

No, there's no such setting. You should be able to just press the AUTO A/C to shut the climate control off though, rather than going to the climate screen.

[jpadc]

Originally Posted by KMO

Ah, found a copy of the relevant page: http://andrew.daviel.org/prius/m_01_0030.pdf

The 4th one down the list of AC options in the document you provided may in fact set something close to what I want. It appear the default for the defrost button is to be "linked" with A/C ON by default. This linking seems to be one way - turning defrost on when A/C OFF turns the A/C ON as well (assuming it was off) but does not turn A/C OFF when you turn the defroster back off. There seems to be a "normal" mode option where maybe they are not linked at all.

So I need to ask the dealer to change this. I assume it requires special equipment to change?

[nyty-nyt]

I wanted to chime in here, because I am becoming disillusioned with my car this winter. My commute is about 12 miles, mostly at 35 mph with no stops. After the 15-20 minutes of driving my coolant is still not warm enough to go into full hybrid mode, only about 64 degrees C, the windshield is still frosted inside and most of the ice is still unmelted on the outside. I'm scraping the inside of my windshield for the first time since owning a 1965 beetle. I've tried setting the temperature to the very first notch above LO, 18 degrees Celsius to get a bit of heat, but hopefully have the engine warm up as quickly as possible.
I have pipe insulation in the grill and I use a block heater which seems to do nothing to help the problem. The last car that did this was quickly fixed by changing the water thermostat. My dealer had the car yesterday and scanned the system before telling me the thermostat is fine. So I'm left with a car that can't generate enough heat in the engine to reach operating temperature, and if I choose to try and make the cabin liveable, the engine loses even more heat...it's really dramatic, and the temperature is just -15 degrees C, or five degrees F. What do the folks in Wisconsin and Alberta do in their Prii to survive? This is my first complaint about the car, and I seem to be destined to be frustrated for another couple of months. Any suggestions or agreement on this problem from cold-weather owners?