2002 Prius problematic symptoms all of a sudden

Good morning,

Before a chorus of guesses chimes in, there are about seven computers that drive and monitor most every aspect of your car, and they are itching to tell you what problems they have detected. All you need to do is connect the right scan tool and let them tell you. However, a usual generic garage or AutoZone scanner cannot communicate with the most important computers in the car. You need a "Prius-aware" scanner, and if you search for that phrase on this forum you'll find a bunch of choices. If you don't want to take the time to hunt something up, the good and fast option is to visit a Toyota dealer and pay them $50 or $60 to hook up a scan tool, read all of the codes for you, and give you a printout with all the information. Some of the codes can have one or more 3-digit subcodes; we need those too.

There are too many things going on here; sometimes a situation involves more than one problem happening to arise around the same time and it can be baffling to try to pin down "the" problem when there's more than one. The battery fan noise suggests the battery is running too hot and that could be trouble in the battery itself, unrelated to the recent work (on the other hand, if the battery was excessively discharged while the shop did the work, it might not be unrelated). The battery computer wants to tell you what's going on here.

The poor acceleration and engine cycling are things the hybrid-vehicle computer is in charge of, and they might be related only to the battery condition or there might be more involved. The HV computer wants to tell you.

The antilock brake system computer is responsible for your brake light and braking behavior, and it has to coordinate braking with electrical regeneration, so it and the HV computer are constantly talking. The ABS computer also gets wheel speed information from sensors at all four wheels and that information is what gets summarized and transmitted to the speedometer display. There could be an issue with a wheel sensor signal (I'm not sure how one could get knocked in the course of radiator work, but things don't shock me as much as they used to), or in one of the communication circuits between the computers. The ABS computer may have things to tell you.

Your Prius radiator is different from a conventional car's because it's combined with the air-conditioning condenser. That means replacing the radiator is also inevitably an A/C evacuate and recharge job (you probably noticed this on your bill, sorry). The engine has to run to drive the A/C and so anything off in the A/C work might affect the engine cycling behavior (if you've got the A/C on). There's an A/C computer that could have useful information there (I'm not sure the scan tool can grab that; there's a separate way to make the A/C computer blink codes on the A/C button light, which you can find in this forum).

People sometimes find that seemingly complicated multi-computer issues can be the result of the 12 volt battery getting discharged to an excessively low voltage, as might have happened during shop work. If you don't have a voltmeter handy to attach to the 12 volt battery for a quick reading, there should be one built into any scan tool (even cheap non-Prius-aware ones), and there's even one built into the MFD in the center of the dash (search "vehicle signal check" in this forum for how to turn it on). You might report back in this thread what you find the voltage to be when the car is not in ready, at a few levels of load (headlights on, headlights and heater fan on, nothing extra on).

If the 12 volt battery needs replaced, that should probably be done before working too hard at tracing other problems. If it shows up strong in voltage checks now, it's still possible it got discharged during shop work, and you could give all the computers a chance to reboot by disconnecting it for several minutes. That might relieve some or all of the symptoms you're seeing, but it will also clear all of the codes the computers are wanting to tell you, so if it isn't the magic fix to your problem you may have lost valuable information. (Some codes will probably come back, but there could be valuable information from the initial cause of the trouble that will have been cleared.)

You might, therefore, want to get a printout of the current information before you try disconnecting the 12 volts.

Hope this helps,
-Chap

 

Bring it back to the shop.

Let us know the outcome

 

You can buy the battery at the Dealer for about $225 + tax. They can install it for $75 if you want them to. The Toyota Battery and after market battery for example Optima is not much difference in price. The Dealer stocks batteries in most cases or can get it from Toyota Parts Distribution the same day.

 

i know at walmart you can get a battery for it. they are like $80 something.they are lead acid instead of agm gel but as far as i know we dont off road with our prius's so i dont think its a problem. i think the number is 51R

here is the link
EverStart Plus 51R Battery - Walmart.com

you could try this if your tight on cash

 

There've been discussions on PriusChat going back a while about whether or not to replace a Prius aux battery with some alternative that lacks a vent hose connection. Quick summary:

• The engineering practice of using a vent hose to outside whenever the battery is inside cabin space reportedly goes back at least as far as VW Beetles. There might be a regulation requiring it but I don't have a citation.
• I'm not sure that all batteries officially offered for Prius are glass mat, but they are all externally vented. What drives Toyota's choices doesn't seem to be concern about off-roading, but simply accumulation of gases in cabin space. (The training materials from Toyota for emergency first responders don't say anything about glass mat, but do promise the responders, page 12, that gases are vented outside.)
• The usual reason for a battery to vent gas is overcharging, which is unlikely in a properly-operating Prius 12V system.
• Some PriusChat members consider Toyota's choice unnecessarily conservative, and prefer to look for batteries in the wider selection of less expensive choices without external venting.

There, I've at least tried to sum up the past disagreements without the level of personal sniping that has appeared in some past threads....

I don't have a strong stance of my own ... I haven't had to change mine yet, it's the upgraded one from Toyota and was installed seven years ago, before I bought the car. That seems satisfactory to me and if/when it dies I'll probably replace it with the same and not worry about it. That's just me.

Posters on PriusChat often come up with alternative ways of doing things that save money or make their own informed judgments on benefits and risks. That's a great thing about this forum. My only concern in this thread is that maybe the original poster is new around here, and a quick comment like

maybe wasn't quite enough to let the OP in on the background so those informed judgments can be made. So I hope I've filled it in a little here.

Cheers,
-Chap

 

Well said.

 

agreed.

My apologies on that one

i didnt even think about the venting. i know my optima thats in there when i got the car has no vent tube hooked up to it at all. so i dont even know where that yube got to.

 

Hmm, I guess some of the Optimas do have vent connections, right? If yours does, you can probably get about any old length of rubber hose and run it out the grommet in the bottom of the battery well. Might even help keep critters from coming in through the grommet. The Official Rubber Hose 28885-21010 ought to set you back about $6....

-Chap

 

Or possibly 50 cents at Lowe's using a clear plastic tube.

Bob Wilson

 

ill check that out. thank you

 

Well you can always take a sledge hammer to I during the Detroit car show. Nah it a Prius not a Bimmer.

BMW M6 owner goes Hulk over defects, smashes own car | Motoramic - Yahoo Autos

 

When I replaced my 12v battery in my 2001 a while back, I just went into Autozone with my stock battery's measurements and ended up finding a Duralast 8AMU1R. Their web site says it doesn't fit the Prius, but with minor tweaks, it works fine. I believe it is actually for a Miata. They list it at about $125. It is a vented AGM battery with about the same length and width as the stock battery, but slightly shorter. Its fits easily in the space, but I needed to use a wood spacer so the hold-down clamp would cinch up tight and hold it in place. Also, it uses standard size terminals (but in the correct locations). This is a pretty easy fix also because the entire negative cable can easily be replaced, and the stock positive clamp bolts onto the end of the factory cable, so you can just replace the clamp. Here are the battery's specs from Autozone's web site:

Product Details

Part Number: 8AMU1R
Weight: 24.0 lbs
Warranty: 5 YR
Notes: Warranty consists of 3 years free replacement plus 2 years prorated. *** 370 Cold cranking Amps (460 cranking Amps) ***. 45 reserve minutes. Check the customer's vehicle, battery installation could take up to 30 minutes. Battery located in trunk. Special 12-volt: 9 3/4" x 5" x 7 1/2". Battery is vented to outside of vehicle (AGM)
Application: Automobile
BCI Cold Cranking Amps (CCA): 370
BCI Cold Cranking Amps Value: Tested to BCI Standard
BCI Designation: U1
Battery Height: 186 mm - 7 5/16 in
Battery Length: 197 mm - 7 3/4 in
Battery Width: 132 mm - 5 3/16 in
Core Charge Applicable: Yes
EN / DIN Designation: Not Applicable
JIS Designation: Not Applicable
Positive Terminal Side: Right
Post Location: Top Post
Reserve Capacity (min): 45
Voltage: 12
MSDS Information: Click to View