Toyota Prius Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter #1
My battery was dead at lunch today. Figured I would let you in on a little bug I may have found in the Prius today.



The 12V battery will die if you follow this sequence of steps.


1.) park with your lights on
2.) open the driver’s side door
3.) power off the car
4.) exit out of the car

Your lights will be on at this point and will stay on. This happened this morning when talking with a friend. I opened up my door and then rolled up my window since we were in a conversation and then powered off my car :)



If you reverse steps 2 and 3 this will not be a problem.



I guess that’s what I get for bragging about my 53 MPG :). I lost that information when the battery died and now I’m averaging 16.1 mpg since I had to sit at Wendy’s with my AC on!

Anyone else ever run into this problem before? My battery died one other time in the past and I'm sure I did the same thing.
-Ryan
 

·
Registered
Joined
·
1,668 Posts
I've not had the dead battery, but I've done the same sequence with my old Camry and with this Prius. Fortunately, the parking lot security called to say lights on. sigh.
 

·
Registered
Joined
·
7,166 Posts
It's not really a bug. It should have been beeping though before you shut the door since the lights were on, but that could have been masked in your mind since it initally would be beeping because you opened your door with the car still on.
 

·
Registered
Joined
·
1,002 Posts
Yup, another way that works to drain it:

1. Start with the car off.
2. Get in the passenger's side.
3. Turn the car on (with the lights on,)
4. Turn the car off
5. Get back out the passenger's side.

Because the car came on and went off with the headlight control in the 'on' position, it turned the lights on, but because the driver's door didn't open after the car was turned off, it didn't turn the lights back off.

(Yes, I know this second way from personal experience.)
 

·
Registered
Joined
·
219 Posts
That's how I found it too, while using my tire air pump, since it plugs in on the passenger side. I went to the driver's side to see if I did something wrong turning it off, opened the door, saw nothing wrong, closed it, and they went off. It wasn't until later that I realized the significance of which door I'd used.
 

·
Registered
Joined
·
1,397 Posts
It seems like a lot of problems could be avoided by just turning off the lights. I have always done that for cars that do not have a specific "auto" feature for the headlights. The Prius does not have such a feature. It just makes an attempt to turn them off for you but it's not the same thing.
 

·
Registered
Joined
·
219 Posts
Is turning off the lights for you fewer steps than closing the driver's side door is for the rest of us? Easier steps to remember? Not sure I see the advantage of doing it that way -- just seems like the old-fashioned and harder way.
 

·
Registered
Joined
·
922 Posts
I don't mention the "auto light" feature to my family when they drive my Prius for just the reasons presented. Going out of sequence can drain the battery, so I'd rather have them turn off the lights each time. (I leave them on for my driving). One problem I've had, though, is my husband not closing the trunk hard enough when he helps me with groceries. Fortunately, someone (DanMan?) wrote a while back that the Prius doesn't allow the battery to cut out completely with trunk left open. Correct? It was not tightly latched for nearly 2 days this week.
 

·
Registered
Joined
·
7,166 Posts
If the hatch is left open, your battery will drain. Many have reported this happening to them. I think the main dome lights will shut off after a time if a door is left open, but I'll have to check on this.

The reason the headlight auto-off acts the way it does is because you may actually want or need light with the car powered off. Also the only way the car can guess the driver is leaving is if he opens his door. If he didn't open his door, he is most likely still inside and still needs the headlight.
You wouldn't want to have to change a tire at night and find that you can't even turn on your taillights with the system off. You might not be seen at the edge of the road and get hit.
 

·
Registered
Joined
·
922 Posts
DanMan32 said:
If the hatch is left open, your battery will drain. Many have reported this happening to them. I think the main dome lights will shut off after a time if a door is left open, but I'll have to check on this.

The reason the headlight auto-off acts the way it does is because you may actually want or need light with the car powered off. Also the only way the car can guess the driver is leaving is if he opens his door. If he didn't open his door, he is most likely still inside and still needs the headlight.
You wouldn't want to have to change a tire at night and find that you can't even turn on your taillights with the system off. You might not be seen at the edge of the road and get hit.
Thanks, Dan, for clearing that up. I hope my drained battery has recharged enough not to have caused a problem.
 

·
Registered
Joined
·
1,028 Posts
Is turning off the lights for you fewer steps than closing the driver's side door is for the rest of us? Easier steps to remember? Not sure I see the advantage of doing it that way -- just seems like the old-fashioned and harder way.
Is getting a jump less annoying for you than for the rest of us? :_>
 

·
Registered
Joined
·
219 Posts
Never had to get one -- the way I turn off the lights is 100% as effective as the other way, of course -- but I expect it'd be the same if I did have to.

If you're interested in getting the point, the point is, there are two ways to ensure the headlights are off in the Prius. One is marginally harder than the other. If someone wants to advocate the harder one, they should present an advantage it has; presumably, that it's easier for them to remember to do, for some reason, and ideally what the reason is.

Of course, if you'd rather just be surly, that's fine, have fun.
 

·
Registered
Joined
·
7,166 Posts
I usually turn off my headlights, but sometimes I forget. Fortunately the pattern that would have me leave them on also allows for the Auto-Off to take effect.
 

·
Registered
Joined
·
1,397 Posts
HunterGreen said:
Is turning off the lights for you fewer steps than closing the driver's side door is for the rest of us? Easier steps to remember? Not sure I see the advantage of doing it that way -- just seems like the old-fashioned and harder way.
I think being easier is more important than being fewer steps. It would be fewer steps for me to leave the window open and climb in rather than incurring the extra step of opening the door and the extra step of closing the door. I do think it is easier to just turn the lights off. Then I don't have to "remember" to turn them off when I drive the car the next time. Leaving them on is not the same as daytime running lights. In the Prius, the tail lights come on when the headlights are in the on position, which I really don't want to happen. When I get where I'm going at night, I can clearly see that my lights are on and turn them off. It is a single habit that can be formed that does exactly what I want and I never need to think about. Like I said, if the feature was a true "Auto" feature with a light sensor, I would agree with you, but it isn't, at least in the US version.
 

·
Premium Member
Joined
·
887 Posts
The auto-off feature that Toyota included with the Prius is not anything like an auto lamp feature that you seen on other vehicle.

Prius auto-off is a stop gap feature to help protect the 12v battery. It was designed to kill the headlights after the car is powered down and the drivers door is opened. However a true autolamp system will turn off the headlights after a time delay from when the vehicle was turned off. Also, true auto lamp will turn on the headlights when it gets dark out and turn them off when it is sufficiently light out.

I do not suggest anyone rely on the auto-off feature of the Prius due mostly to the need for a specific order of events to occur for this feature to work.

A simple solutioN to door ajar dome lamp on situations is to look at the dash at the are of the door ajar light when you exit the vehicle. If that light is off, your dome lamps will also turn off after their prescribed on time has elapsed.
 

·
Registered
Joined
·
219 Posts
redwein said:
I do think it is easier to just turn the lights off. Then I don't have to "remember" to turn them off when I drive the car the next time.
Ah, there's the answer. Hadn't occurred to me there are still people doing that. So we'll see from Hep's survey how wrong I am about that.
 

·
Registered
Joined
·
219 Posts
jeromep said:
I do not suggest anyone rely on the auto-off feature of the Prius due mostly to the need for a specific order of events to occur for this feature to work.
But that order (closing the driver's side door after the car is turned off) is no more dependent or difficult than the order required for the "turning it off manually" feature to work.
 

·
Registered
Joined
·
1,397 Posts
HunterGreen said:
redwein said:
I do think it is easier to just turn the lights off. Then I don't have to "remember" to turn them off when I drive the car the next time.
Ah, there's the answer. Hadn't occurred to me there are still people doing that. So we'll see from Hep's survey how wrong I am about that.
Why would you leave the headlights (and taillights) on in the daytime? Most "Auto" headlight features, even those with DRL don't do that with the taillights.
 

·
Registered
Joined
·
1,028 Posts
Never had to get one -- the way I turn off the lights is 100% as effective as the other way, of course -- but I expect it'd be the same if I did have to.

If you're interested in getting the point, the point is, there are two ways to ensure the headlights are off in the Prius. One is marginally harder than the other. If someone wants to advocate the harder one, they should present an advantage it has; presumably, that it's easier for them to remember to do, for some reason, and ideally what the reason is.

Of course, if you'd rather just be surly, that's fine, have fun.
http://www.youtube.com/watch?v=SLbFDMplZDs
 
1 - 20 of 26 Posts
Top