wife's prius is freaking out

first, check the negative terminal on the 12v battery. next, check the voltage on the 12v battery. some reallllly strange things happen when the 12v is having issues.

 

try this first. disconnect the negative terminal for 1 minute, then hook it back up and see if it starts up. it may also be that the 12v is just dead and isn't going to recover after a jump.

now on this park lock mechanism thing... assuming the car is in park, can you open the door, stick your foot out the door and push the car forward with your foot? (think skateboard)

if not, then the park lock mechanism is not abnormal. if so, that needs to go to the dealer for sure.

 

Tadashi,

How did the issue with your wife's car resolve?

My car is showing some of the same symptoms - blinking P, D, N & B squares, triangle with exclamation mark (master warning), SRS light, tire pressure light and Maint Reqd - and most troubling of all, it won't power up at all so I can't even take it to the dealership without a tow. I tried disconnecting the negative terminal on the 12v battery as suggested below, but no luck. And also it doesn't look entirely like a battery issue because the interior lights are still functioning. It's only got 2600 miles on it and was functioning normally in the morning. The problems only cropped up when we hopped back in later for an afternoon outing.

Any add'l thoughts would be appreciated.

 

I too would be curious to know, any updates?

 

For reference, when the car tells you it's on uneven ground, you are almost always facing an issue w/ low battery voltage. The 12v needs to be recharged, either by letting the car run for a long time (charged by the HV side through DCC converter, approx. 1 hour) or put it on a *low current* battery charger. Conventional chargers will damage the AGM design.

The core question is why this happened in the first place. Was the car left sitting for an extended period? Or was something left on?

 

<div class='quotetop'>QUOTE(Tadashi @ Jul 10 2007, 11:04 PM) [snapback]476573[/snapback]</div>

I'm curious.... How does the Prius let you know that it thinks it's on an uneven surface? Is this a message on the MFD or a code you looked up from a DTC scan tool? Does it talk to you?!?!

 

Thought I'd pop back in with the coda on my post. Turns out it was a dead 12v battery after all, although I'm not sure how it drained down. Must've been a door ajar or something. We tried jumping it with our conventional car, but no luck and so ended up needing to tow it to the dealership where they put it on a charger for several hours. (We didn't have one, but will be getting one directly!) Seems to holding the charge for now. Thanks for insights.

 

I had the battery go low when I had the window tint put on. (they left the ignition on too long, they needed it to roll the windows up and down).

The car acted very strangely when I tried to start it and looking at the warning lights on the dash the manual told me to have it taken to the dealer. I thought that was silly and turned to the jump start instructions in the manual. I followed the instructions, but still had a very difficult time getting the car to start. It kept telling me that there was a problem with the "parking switch mechanism". After fidling with the start button, foot on brake, foot off brake, fidle with park button, etc. It finally started. I don't remember the exact sequence I had to follow to get it started, but I was a bit irritated. I tried the jump start procedure in the manual, and it did not work.

Specifically, two things bugged me about this experience;

1. The battery was not dead, just low. The prius should be able to tell me that the battery is low, and not just give me a warning light that tells me to call the dealer. I mean, a battery going dead, or low is a common occurance. Especially for a Prius with its tiny battery.

2. The detailed jump start procedure in the manual should have been able to get me around the error messages, but it didnt. I had to fiddle with my own procedure to get it to start.

 

It also sounds like it may think the driver's door is open. That would jive with both the parking warning and the headlights not turning off, since opening the drivers door tells it to turn off the lights. Perhaps there is an intermittent in the door sensor switch or associated hardware. Does the door ajar light come on when you don't expect it to?

 

I've had a similar experience before:

I took my Prius to a local Green Building/Hybrid Expo and was allowed to have it right in the middle of the show. Of course after having all doors open for two days straight (closed overnight) was enough to drain the tiny 12V battery. I first noticed the dead battery on the 2nd day when I closed the rear hatch to show someone the rear view visibility and it wouldn't open again (I remembered reading the owner's manual about the lever you can reach by crawling through the car to pop open the hatch door). So, I immediately looked at the light on the bottom of the drivers door and saw that it was dimmer than usual so I knew it was going dead. I tried to power up the Prius and got nothing.

So, I waited until the end of the day when everyone was finally packing up to leave and was able to borrow a 12V battery from a guy in the process of building an electric car (fortunately he brought a battery with him to demonstrate how it would fit in the battery rails) and he also had a set of jumper cables. I connected it exactly as the owners manual said to, then tried to power up and got all kinds of strange lights like you mention (squares around the P/N/D/B, and the triangle, then the message on the screen about parking on a level surface and applying the parking brake). I immediately put the parking brake on, I guess that's one of the Prius safety features to disable the park mechanism if the battery dies so the car will be in neutral to be pushed or towed without having to be powered on. Wasn't sure what to do, figured it would have to be towed to the dealer by then, but I just turned it off and left the spare battery connected for a good 15-20 minutes and tried again, everything worked just fine but I was still getting some crazy lights for a few more days.

Almost like some people say when you get crazy lights after installing the EV mod you have to power off and on about 3 or 4 times to clear out the problems and get back to normal, that worked for me and after a few days it went away and is now back to normal. Also, leave a well charged 12V battery (or jumper car) connected to the jumper points for at least 15 minutes or so to give the Prius battery a chance to build up a charge.

Also, to make sure your auto headlight shut-off is working... make sure the Prius is powered off before opening the drivers door. If you open the drivers door first then power off, the headlights will not auto shut-off.

 

Re: wife's prius is freaking out

The solution of letting another vehicle idle for about 30 minutes while connected with jumper cables was able to solve my problem. I had parked on an uneven slope, engaged park, and set the emergency brake. Once opening the door the constant beeps started as if you hadn't taken your key out and the door was open. I didn't pay any mind, but 8 hours later the vehicle was dead in the water. The Prius manual's recommendation of allowing 5 minutes of 2000 rpm from the jumper vehicle was unsuccessful, so I would say give it a long charge from the jumper vehicle or from a battery charger.

I appreciate the forum and information!

 

Re: wife's prius is freaking out

Sorry to say it but if your 12 volt was that dead its done. Even minor sulfation impacts that little battery greatly. It is now a time bomb waiting to go dead at the most inopportune time. Or at the very least it will now kill your mileage as the engine will have to run alot more to put a charge on that sulfated battery.

 

Re: wife's prius is freaking out

If you have an 05 Prius and are on the original 12 volt battery, even w/o running it flat via the above, you were due for a new one. You should get it replaced ASAP. The 12 volt does NOT start the ICE (internal combustion engine) on the Prius so you will never have symptoms of slow cranking nor starter unable to start the ICE.

Many recommend an Optima Yellow Top (http://priuschat.com/forums/prius-h...-12v-yellow-top-d51-battery-pencil-posts.html) instead of an OEM replacement. I've got one in mine now but prior to availability of the above, I went with Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11.