12v Battery Initialization Procedure

there is nothing different in changing the battery in a prius vs any other car. The prius has a vent tube that other batteries don't have, pull off the vent tube of the old battery, attach it to the new battery. But it's basically the same positive negative connections. Take apart the old one and put in the new one. Take off the negative first, then positive. To install, put back positive then connect the negative last.

When you are done, you have to reset the drivers window up and down. Roll the window down about 1/2 way and then roll it back up. Just doing that will reset and reprogram the window to automatically go up and down.

Redo all your radio presets like any other car radio, just tune to the stations you want, hold the buttons 1-6 preset until it registers your presets.

The clock is the same, set the hour and minutes like any clock

 

Here's some details on the swap. Should take an hour, depending on your skills. Read the attached pdf for all the info.

JC above explained the initialization. Really no magic involved. Don't freak out if the gas gage doesn't work on first go around. Takes a little bit for it to read the sensor. Some folks report needing two pushes of power button to get Prius completely booted up.

My best advice would be to make sure the battery is fully charged BEFORE you install it.

A AGM type battery for the Prius should measure 12.8 MINIMUM when fully charged at the posts with a digital volt meter and NO LOAD applied. Don't accept a poorly charged battery. Check it before you buy it. Just because it is new does not mean it will be fully charged.

Best of luck to you and "Welcome to Prius Chat".

 

I am not aware exactly where this pdf originated. It is posted here on Prius Chat in the "file section" of the forum. uart | PriusChat is the actual poster of the file. I simply grabbed the file and saved it on my drive to help folks like you. It is very detailed as you have seen.

Procedure for 12V battery replacement. | PriusChat

In reference to step #10 (initialization), the only thing that you need to initialize is the "auto window" for the drivers door. To do this you start with the window raised all the way up. Then lower the window down halfway. Then raise the window back up and hold the switch for at least one second AFTER the window has raised up to the top. That procedure will initialize the "auto window" whereas it will work properly.

The only other stuff that needs to be done is to reset the radio stations as they are lost when the battery is disconnected. You will also note that both trip odometers will have been reset as well as the MFD being reset.

As I wrote earlier, there really is no magic in all of this. 99% of the job is just labor.

For a quick and dirty explanation look in my signature file below. The second link contains a rough write up I did that describes the removal and installation of the 12 volt when I did ours. Refer to post #8 for more info.

Also my best suggestion to you is to use white lithium grease on the screw head of the top screw that holds the traction battery vent duct into place. The purpose of the grease is to hold the screw in a socket and a extension while the screw is level (horizontal) without falling out whereas you can stab the screw back into the hole. When you get in there, you will see what I mean. You don't want to drop that screw as you would need a pickup to retrieve it or pull everything back out to find it.

Best of luck to you. Don't sweat this job. It is a DIY job if you have basic mechanical skills. I did it, and I am disabled and arthritic.

EDIT: I will go one step further. If cyberpriusII can do it, I have no doubt you can. See her adventure here: Won't Turn Off -- Master Warning Light on (Red Triangle) | PriusChat

 

Maybe it depends on the generation, but I've heard with the negative cable it's easier to disconnect the cable at the end it bolts to the body. Obviously the cable also has to be disconnected from the old battery, but that end is hard to get at when the battery's still in the car.

 

On the Gen II it is definitely easier to disconnect the negative at the body rather than the battery. The clamp is hard to get to whereas the bolt head is real easy to reach. It works best if you swap the negative cable from old to new battery once the dead battery is removed from the Prius.

Can't say about Gen I or Gen III as I am not familiar with it.

 

Yeah, you can do it that way if you don't mind wiggling the battery around a little. Glad to hear you got a handle on it. Remember negative is last connection. Don't fret the sparks... I say that since another poster did.

Have fun.

You haven't mentioned this, so I will ask.

Which battery brand are you going with? OEM, "Yellow Top", Exide, or what?

 

TWELVE minutes!!

I am crushed. Totally crushed. Well, maybe I could do it in 20....maybe. Listening to my "elders" and taking off the negative cable from the wall of the car first would speed me up quite a bit....

My Chilton's manual says you have to initialize the windows after battery replacement -- which I did. It mentions nothing else. The Toyota owner's manual says you have to do the windows, the tire pressure system and, the scary " The hybrid system may not start"

But, it does not say what to do if it does not start. No matter, all I had to do was the windows and turn off the reverse beeper, again.

 

Just finished replacing my 12v Battery..

My battery actually failed or died on me.. So here is what happened.. I got about a half of a block from my house and 4 warning light came on (including the Triangle of Death).. I have my owners manual to help me recall which ones they were..

Red Triangle, Battery, Brake, (!) Yellow, and I think VSC not sure. At the same time I was getting warnings on my MFD Panel. This was very distracting as I was trying to ascertain just what was going on. The were two warnings on the MFD first was BAT and the other was Brakes.
I immediately turned around and headed back to the house, it shut of on me completely, just as a regular car when it dies, no power steering, and brakes difficult to manage.

First think I did was check the 12v Battery with a volt/ohm meter. I was only reading 11.2 Volts.. Looking at the battery, I believe it is the original one from the factory. My car is a 2008 with 95,XXX miles on it. I purchased it a year ago with 86K so I don't know the history on it.

Replacing the battery was pretty straightforward but I did want to document that on the first attempt to start the vehicle, I continued to have several of the same lights on the dash and didn't get the "Ready" that I had hoped for. I came in the house and did another PriusChat search to see if there is a first time startup procedure after 12v Battery replacement. Their didn't seem to be only that the auto window needs to be reset. One person mention that you may need to push the Start button twice. I went out to try that but is shut the car off, so I pressed Start again and it come up and on-line or "Ready"

One thing you need to be prepared for is the Gas Gauge will be flashing one pip.. I sat in front of my house until the ICE kicked on.. I waited until it shut off before proceeding on my test ride. I drove nearly a mile before the Fuel Gauge reset and show me back at 1/2 of a tank. With all of my warning lights off, I felt confident that all was well and headed back to the house. Once parked at the house, I rolled the window half way down then back up to reset the auto up function. Then I adjusted my clock and turned the vehicle off.

I would recommend that if your battery is more than 4-5 years old, you should replace it or have it done for you. It's not a good feeling when the Prius lights up like a Christmas Tree and quickly shuts off on you. Having said that, I plan to replace the wife's battery right away before I really get into trouble!!

 

Your battery should not have caused your car to shut off. If your car shut off while it's in "Ready" mode, you have another issue. A bad 12v will only cause your car to not start.....not shut off while "Ready"

 

The only other warning that meant anything to me was Brakes. With the 12v reading only 11.2v it looked like a good place to start. I wouldn't restart with the old battery. I tried to put the car into the maintenance mode but each time I turned the headlights on and off, the MFD reset. I had the instructions printed out and watch the YouTube Videos ...

I have a ELM 327 and Torque on my Droid, tomorrow I will check for DTCs.. I hope it's only the 12v ...I haven't have any problems since I bought it. The only things I've done is changed the Transaxle Fluid, Replace the Anti-Freeze Fluid in the ICE and Inverter, and replace Spark Plugs. I'm planning on keeping it for at least 4 years or 160K whichever comes first. Fingers crossed

 

No codes... She's running great!

 

When I replaced the battery on my daughters Prius I first connect a small 12v battery to the jump start terminals under the hood. If you do this before removing the battery you don't have to mess with the clock, window etc since the cars power is never interrupted.

 

Tell them Star! It's senseless to go through all that hassle! Just put a jumper under the hood at the fuse box .

 

I have a jump pack with an incorporated cig lighter style outlet. I got a cable with the cig lighter plug at one end and OBD plug at the other end, with just the 12 volt pins. It has indicator light as well, so you can verify connection is good, at both ends.

Lay the jump pack in drivers foot well and hook up cable at OBD port, you're good to go.

Memory Saver Cord - ESA30 | Call us at 1-800-328-2921 | Clore Automotive

 

Anyone have a problem with the MFD not operating after battery replacement? When I first replaced the battery, I started the vehicle (2008) last night and all showed up, with the single pip on the fuel gauge as noted.
This morning when I started, everything showed for a moment, then when I switched to Drive and pulled out of the driveway it all disappeared.

The center "computer" screen works, showing driving info, mileage, MPG etc, but the display with speedometer, fuel gauge, etc. is blank. I had the computer replaced under warranty a few years ago, I hope I don't need to do that again!

**Edit**
Guess it is not the MFD, but rather the CM - the display that shows speed, mileage and so on. I saw the thread on the CM extended warranty, but apparently my 2008 does not fall into that category due to time (DOFU 102/2007) and VIN

 

JWIT

Just to be sure, I would recheck all your connections at the 12v, make sure all the cables are tight.

And, was I insulted by DoRunRon earlier in this thread???