A Sick 2001 Prius

Hi John,

Has your commute pattern changed, so that you now drive extended periods downhill?

If no, then my evaluation is that the reason you are seeing green bars is because your battery's capacity is reduced. Hence, less energy is required to charge the battery up to seven or eight green bars.

 

I have a question for someone who has owned a G1 and a G2. I have a G1 and had similar problems as the sick 2001 until I changed the Traction battery. My question is the G2 which has a different indicator than the G1 indicates a lower SOC with a new or good battery than my G1. Before I changed my battery, The green battery indicator would go from 1/4, 1/2, to full battery, up and down while driving. After changing battery's, It stays full green all the time. Is this normal??? Thanks Roy

 

Nope, same old commute for many years now. And I have not noticed dropping to 2 bars more often. In fact, that is still a rare occurence.

So... how is capacity measured? I wouldn't expect it to be dynamic (percent of maximum) like that. I'd think it would be a kW value.

.

 

The definition of weak is a pair of modules with more than 0.30 volt difference in operation. So your pair:

16.42
16.17
-----
0.25 V. ~= 0.30 V. under load

The test procedure puts the vehicle in a slow discharge mode and during the sweep, the problem occurred.

We can actually map out the module pairs from the control electronics:

P3011 - closest (I need to check my book it may be P3010)
P3012 - next
...
P3039 - furtherest (again, I need to check my starting code)

These NiMH batteries are something else. The charge and discharge curves are such that it is nearly impossible to use voltage unless you bring down to the lowest state of charge or up near the maximum. Otherwise, they "look" OK. Very, very tricky batteries to deal with.

You have these options:

1. timely battery replacement using Toyota - expect to pay $4.5K and lose the car for a day. If you can, get the old modules and let me know.
2. find a salvage battery replacement NHW11 - you are buying a 'pig in a poke' and it may be a great deal or a pack just ready to fail. Expect to pay from $500-$1,500 and a day or so of work. Without tools or expertise, a challenge and you may still have just swapped the Devil for the "deep blue sea."
3. HIGHLY EXPERIMENTAL buy two NHW20 packs - very experimental, replace the 38 NHW11 modules with superior NHW20 modules. However, this is an experimental process and likely to be expensive since two, NHW20 packs are needed to make one NHW11 with some NHW20 modules left over. Expect to pay $1,500-3,000.
4. Experimental refurbish the NHW11 modules - an experimental process, this takes about 3 weeks and you must have a second car during this time. You'll also need a work area, a place to keep the car parked, a quality battery charger, MRC 989, JB Weld, patience and a friend and/or hand truck to help you move the 80 kg traction battery out of the car to the work area and later, back. You will be replacing the lost water by; (1) drill two small holes; (2) lay flat; (3) fill one hole with distilled water until it shows up at the other; (4) turn upright; (5) seal one hole with JB Weld, throughly; (6) put on MRC 989 cycles to reactivate electrodes; (7) seal remaining hole and use 'ice cube' trick to make sure it is throughly sealed; and (8) one full cycle to confirm JB Weld seals. You will do this 38 times although we may be able to cut that down to 19. My attempt to reduce it to 13 times revealed a problem with the MRC 989 that is out for repair. The actual labor runs about 30 minutes, once or twice per day, the MRC 989 does all of the work. However, it takes calender time.

Bob Wilson

ps. If you decide to try #3, don't let any of the NHW20 owners learn about this new drain on the pool of salvage batteries. <ssssssuuuuuussssssshhhhhhhhh>

 

Then go with the tech's advice. He is the man on site with the vehicle, diagnostic system and Toyota tech support on speed dial.
...

The tech is the man on site with the vehicle, diagnostic system and Toyota tech support on speed dial. I have no interest in replacing him and you've already asked once. Go with the tech and we'll enjoy hearing how it turns out.

Excellent! Including installation labor? This is a great price break. The last Texan who reported a battery replacement said it cost "$6,000". This is great news.

Bob Wilson

 

Hi Roy,

A healthy Classic traction battery will usually show either 1/2 or 3/4 battery icon almost all of the time. I'm not sure why your car is showing a full battery icon (where no black is showing within the battery icon outline).

A healthy 2G traction battery will usually show SOC ranging from two red bars to eight green bars. Usually the green bars are achieved after a period of downhill driving.

 

Hmm, if the excess power is going to spin the engine, then I do not see how this correlates to the 12V bus voltage increasing (as evidenced by light brightness increasing.) My guess is that voltage fluctuations are evidence that the DC to DC converter is having a problem regulating the bus voltage at ~13.8V.

What is the name of the ECU that requires replacement: battery ECU, hybrid vehicle ECU, or ?

I agree that $2,900 is the MSRP of the battery itself; typically the labor charge will bring the total price up into the $4K range.

 

The test procedure puts the vehicle in a slow discharge mode and during the sweep, the problem occurred. (Bob Wilson).
I didn't know the Toyota procedure used to check the batteries. What Bob says is the first explanation I have seen of the procedure. I would think a pretty good load would be needed to set the P3006 code on a marginal battery. I think maybe you could put the car in reverse with the scanner connected and apply accelerator to put a load on the battery, with brake applied and see if the code sets would be like a load test and give a better indication of the actual battery condition. I have no idea if this could be dun with their scanner. I think it would work with a regular scanner. (I will try this with my car later today and report back.) I read somewhere, I can't remember where that it takes 1.2V difference between groups to set the P3006 code. Therefore I think more load is being put on the battery while driving than the Toyota procedure is putting on it and that is why the battery is testing in the normal range when they test it. Thoughts by anybody else?? Roy White
Hi Patrick, Thanks for your response. I am going to try the above test to also see if my battery indicator will go down to less than full. I am curious as to why it never goes lower than full charge. maybe it has and I just didn't notice it. At any rate the car seems to be happy. That also makes me happy.
OK, I ran the above test. With the car in reverse and the accelerator on the floor, the battery indicator stayed at full charge for four minuets and then went to half way. The ICE stayed off. Continued on to seven minuets. The ICE came on and started charging the battery, The reverse shift indicator started flashing. Ended test. This put a pretty good load on the battery and if it was bad I think it would have put the failure light on. No codes were set so I think I have a very good battery. I drove the car around the block a few times and the battery went back to full charge. Roy

 

2+4: buy a pig-in-a-poke salvage battery, spend 3 calendar weeks refurbishing /it/ (assuming the car still gets you around), then swap the two and refurbish your old one, or swap first if the car already won't go.

Aren't there enough more NHW20s around than there were NHW11s ever made to prevent that having too significant an impact?
-Chap
ps. agree the symptoms seem weird enough (especially the brake and converter output anomalies) that I could easily believe an ECU is haywire. This is where it would be really cool if the dealer *had a known good ECU on hand* and could try swapping the ruddy thing in the name of diagnosis.

 

It is your car and your technician. However, if you can keep the old parts, I would be interested in buying the failed parts.

I'll offer $250 and pickup up shipping for the battery. I use old, failed batteries to work on the battery refurbishment process.

Bob Wilson

 

Not sure how to start a new thread here, but I also have a sick 2001 Toyota (109,000 miles) in Central Texas. Calling around to various dealerships regarding the HV battery on first generations. I found that the Killeen dealership had to replace the HV battery with a trade in that sat too long on the lot. San Marcos had 3 vehicles come in. One needed the battery, computer and cables replaced. The second required just the battery to be replaced and the third car in refused the repairs. They thought the heat was having something to do with the number of cars needing batteries.

My car's problem is that I have P3006 code indicating that battery readings are not level across the cells. Several are very low. One dealership told me that I will have to get the computer replaced along with it because the computer and battery might not sync up if I just replaced the battery. He said the computer might think that the old battery is still there. Since this is an additional $1000, I'd like to know if "might not work" makes sense to anyone. Do I need to just trust the guy and shell out some more bucks? Is this code indicating that the computer does need to be changed also?

The other thing wrong is that there are error codes for the catalytic convertor and my dealership says it needs replacing. I had the car taken to another repair shop for a second opinion and they said the converer output was fine, but it looked like the oxygen sensor was putting out a faulty reading. Big difference in the price of those 2 repairs. Any thoughts?

 

I had DTC P3006 on my 2001 at 61K miles. Only the traction battery was changed. Unless the battery ECU is known to have a problem, I recommend that you decline that repair.

The second oxygen sensor (downstream from the catalytic converter) is the one that lets the engine ECU know if the catalytic converter is functioning properly. I recommend that you authorize replacement of that sensor to see if that solves the problem (the engine ECU probably logged DTC P0420.)

Good luck.

 

Can anybody tell me what the warranty is on a new battery? Does it have to be installed by a licensed Toyota dealer for the warranty to be good?

 

The warranty would be the same as that offered for any Toyota replacement part: 1 year duration

HV = hybrid vehicle. That ECU is located behind the glove box in the passenger cabin. The ECU that is located within the battery enclosure is the battery ECU.