'98 prius questions

[Levi471]

Hi, All,
I am new to the site and have only just purchased a '98 Prius that had a dead HV battery. I recharged the battery by first charging up to about 60 V before I could activate the onboard charger. Now all things operate, but don't know the ins and outs of the car. Firstly, when I reverse, the engine shuts down and the car works prefectly on the battery. When I stop, the engine automatically restarts and keeps running. When I drive and accelerate, the turtle comes up. If I immy reduce accelaeration all is ok, if I continue to accelerate, the turtle stays on and the car slows down, requiring a reset before I can use it normally. Any info for me, please? I am really interested to get this thing working properly again. Secondly, the MFD only has a backlight. No display. Help!

 

[Jeremy Harris]

I guess that this is a JDM only Prius NHW10 as I'm pretty sure they didn't release the Prius on general sale outside Japan until around two years later. The NHW10 has a long list of known faults that relate to the Turtle display and your best bet is to go to one of the dedicated Prius forums and ask. This section of Priuschat sometimes has stuff on the NHW10, and there are a lot of Prius experts there who may be able to offer you some advice: http://priuschat.com/forums/toyota-hybrids/

One really big problem is that, because the NHW10 was effectively an experimental model, only sold in Japan, the displays will all be in Japanese once you get them up and running, so unless you can read Kanji the MFD probably won't be much help to you. The OBD is also non-standard, so the normal diagnostic tools that work on the full production Prius models (NHW11, NHW20 and ZVW30) don't work effectively on the NHW10, which is a pain when it comes to tracking down faults. No Toyota dealer outside Japan has the diagnostic tools for the NHW10, either, as Toyota only ever distributed them inside Japan, to the few dealers who were part of the initial hybrid launch there.

Lastly, the NHW10 has known HV battery problems and replacements aren't available. Some enterprising souls have fitted NHW11 systems into the NHW10, but it isn't a straight swap and requires some jiggery pokery to get things to work.

Whereabouts are you? I ask because the NHW 10 is very rare outside Japan, it's only ever been exported second hand to other countries by non-authorised dealers, usually because it's too old to be worth putting through the Shaken, the very tough Japanese roadworthy tests that older cars have to pass three years after purchase and then every two years.

Jeremy

 

[evblazer]

If I remember correctly to my wifes first prius reverse is electric only so the engine will cut off.
The turtle is the battery going low and the engine is being used to recharge it instead of providing power to move which on accelleration isn't any good.

 

[Jeremy Harris]

I've just done some digging around the web, as I had a feeling there was a group better suited to answering NHW10 Prius problems, and have found it, here: http://autos.groups.yahoo.com/group/Mk1_Prius/

Someone there might be able to help, but I have a sneaking suspicion that you're in for a fair old technical learning curve trying to sort the car out. I suspect that the problem is with the HV battery, which was made up of a big array of D cells on the NHW10. These proved to have problems and didn't tend to last as long as Toyota wanted, so when they put the Prius into full production they fitted a completely different battery pack, using 6 cell NiMH modules.

Jeremy

 

[Levi471]

I'm in Dublin. Makes me feel a whole lot better(sic).The car is a Jap import and was sold to me as a non runner due to the dead battery. The mechanic thought the the engine had a problem due to the non start, but after checking the internet, realised that the engine starts from the HV battery through the generator motor. I did read that the display is all in Japanese, so thought as much as far as the info is concerned. I have noted that the turtle light goes out after a while when I'm just charging (leave in park and running).
Interestingly, though, is that when I do an OBD check on it, the fault is recognised as an overvoltage to the brake system!.
I'm hoping that when all the snow os gone that by normal driving the battery will charge and react normally. Do I live in hope?The HV battery was charged about 4 weeks ago and I start the car about once a week. No problems there.
I take it that the ICE normally runs in drive?
I

 

[Jeremy Harris]

There is a chap in the UK who has one or two NHW10s and has done some work on them. He's a car dealer or repair chap (not sure which) but he posts on the UK Prius group (in case you're wondering, I'm in the UK and am now on my second Prius, a 2010 T4, hence the Prius geekiness......). The UK Prius group is here: http://autos.groups.yahoo.com/group/Prius-UK/ so asking an NHW10 related question there might provoke an answer. I do know that he tried transplanting NHW11 parts into one and converted one to run on LPG, so I'm pretty sure he knows a fair bit about them.

The OBD might be giving duff info, as the protocol used on the NHW10 is very non-standard. There are a few S2000 diagnostics units leaking out of Japan, and these will diagnose faults via the OBD port, but the menus are in Kanji and it's ..............

I very strongly suspect the HV battery as being the cause, as I mentioned before. MrMik here has been playing with NHW10 battery sticks, so knows a fair bit about them. They are essentially D type cells (made by Matsushita (Panasonic) I believe) and may possibly be similar to the cells used in the Honda Insight. Finding a replacement battery for an NHW 10 is near impossible, as they were never properly supported by Toyota in the first place, so the only real way to repair them is to find some way of replacing the cells. At 12 years old the originals are almost certainly near the end of their life, unfortunately. It should be possible to build a new battery pack from NHW11 cells, as although these are a completely different design, they are still NiMH cells of a similar capacity. They are not a straight swap because, although the car body shape is fairly similar, the battery box space/boot floor is quite different between the two cars.

The ICE will stop and start when in drive, depending on speed and load. It shouldn't run all the time, if it does, then that's an indication that all's not well, probably with the HV battery not accepting charge properly or being out of balance as a result of some duff cells. The ICE should shut down below about 25 mph, provided that the battery state of charge is high enough and that the power demand is not too great. The ICE will cut back in again if accelerating or if the battery state of charge drops. The ICE will run all the time at speeds above around 25mph. Reverse is always electric only, the ICE cannot provide any power to the road wheels in reverse.

Jeremy

 

[Levi471]

Thanks for that, Jeremy.
It's a very interesting project, though.
I have looked at Mr.Miks site and find it very interesting about the 'D' cells. I will look at that as a project.
I have had the battery box open as I had to do that for the initial 60 volt input (had to bypass the relays). Anyway, was well pleased with myself for getting some charge back into the battery and getting it on the road. I will soldier on and let you know bit by blow bit.
Thanks for any info that may come my way.

Regards / Tony

Additional:
Just drove it again today and for the first time it responded to forward electrically (that is, engine shut down and car drove on e-motors perfectly) I'm hoping that, as time goes on, that the car will start to behave itself when the batteries become charged sufficiently.

Live in hope?

Tony