Hymotion is dead. Do I have any hope for a fix?

That would be great! The second plug lost prongs about 6 mo. ago so I stopped using the L5 but continued using the Prius. I replaced the plug and cover door two days ago and tried to charge the L5. The break lights blinked as if charging but not so. The car will not start when plugged in which is as it should be. The indicator light on the switch does not come on at all. The display does not show the L5 battery. When I plug it in a "Kill-a-Watt" it shows the car is drawing 14 watts. We turned the car on and off 5 times as shown in the owners L5 manual and we pushed the reset circuit breaker on the L5 but no change.
In 2008, I ordered the L5 and got a Prius with 100k on it as "tuition" to learn about 21 century cars. I guess I'm about to get a big lesson! It's got 185k now.

Thanks

 

I have downloaded the PCM diagnostic troubleshooting guide and Installation PDFs and will try to make some logical conclusions and will be back on line soon.

If the "diagnostic software" was available and I knew how to use it might go faster.

P.S. Fitzgerald Toyota of Gaithersburg, MD, where mine was installed in Sep. '08, also mentioned using Sybesma's Electronics to repair L5's

I'm a scientist but I'm thanking God for this forum!

 

You'll want to see if the power LED is flashing a code when you plug the car in to charge it. Having a trouble code to attack makes it a whole lot easier to make an effective start. We'll help you however we can. Good luck!

 

OK, I'll check for flashes on the LED switch light when I plug it in. I have not seen any light from the switch light in several months, since the blade pulled out of the plug. I was expecting, that after I finally replaced the plug in the bumper, everything would go back to normal. It had been reliable for nearly 6 years and 88 k miles. The car now has 188 k. (I thought it was 185 but no, time for another oil change) So far I've only been looking at the tail lights. Tonight, I'll plug it in the Kill-a-Watt and give you all the results tomorrow. THANKS!!

 

Now when, I plug in, the only indication is that, nothing happens when I try to start the car. I just tried it as a test. The car runs fine when not plugged in. For the first two days after I changed the plug, the brake lights would flash. Seams like it's getting worse!

 

Have you checked the crash sensor?

 

Usually the crash sensor should cause a blink code, but it doesn't hurt to check it I suppose.

 

Just reset what I THINK is the crash sensor. Is it the hole on the top, left, rear of the L5 cover? I pulled the rubber plug and very cautiously pushed with an insulated handle screw driver. I pushed against something on a spring but it did not stay down, so I don't know if it was reset or not.

The LED does not light at all. The brake lights DO come on when I plug-in, I think it needed to do some kind of "reset". It is still only drawing 0.1 to 0.2 Amps. 120V ac. Since I don't have any code what should I do next? Check for power at the L5 on switch? I found a 9 pin, female, RS232 plug and another automotive type male plug on the left side of the L5. Both are disconnected and I assume for problem diagnoses.

 

Hello wb9k & ericbecky,

I just finished another Prius oil change and took a break to chat with my new best friends, you guys. I found the A123 Hymotion Battery Pack thread from a couple of months ago about damage caused by not charging. The plug broke on my 5 1/2 year old L5 and then we had a very cold winter, so I'm thinking that's not good.

I did see the procedure you posted for checking and replacing the cells. I am almost set-up to do serious work like that, but sure hope I don't have too!

 

My next thought was that you may have a low cell. Sounds like this is a real possibility?

 

I left it plugged in over night. About 0.23 KWh went in. I decided to check if the switch on the dash had power. So I popped the switch out of the dash and poked it with my multimeter probe. While I was poking the ground probe in the door jam, the LED started blinking. First time I've seen it on in 4-6 mo. 10 short blinks and then a long one. From another one of your replies that's 11 blinks and means a low voltage cell. Is there any chance that if I keep trying to charge it the voltage will creep up? If not do I need to pull the L5 out of the car to "bench charge" the offending low voltage? Will I need a special charger or could I use a Lambda variable voltage DC power supply?

P.S. We make all our electricity w/ PV.

 

Bench charging is going to be the only way to really assess what is going on.
If it were me, I would focus on opening it up and working on the low cells.

 

Agreed. There's really nothing else to be done here. John, you should be able to use the paper I wrote up on this to guide you through the process. Let me know if you have questions. Bench supply is fine, use a decent meter to make sure the voltage is set precisely. Repeatability of measurements is more important than absolute accuracy for this job. You'll want to mind the position of the low cell group(s). Some cells can only be charged easily through voltage sense connections that can't support more than a few amps. Be sure the module's internal connections can survive the current you supply!

If it's only been a few months since this thing worked, I wouldn't get too worried just yet. You probably have a cell group that is not holding charge quite as well as it should for one reason or another, but it may well be fully recoverable. Keep us posted.

 

Thank you both! I have your paper but don't know what's needed to bench charge. Could you post a link for some basic "How to" info? I'm technical and mechanical, have lots of mechanic tool, several mutrimeters, high voltage gloves, a small Lambda DC power supply and even a very old Tectronics oscilloscope. I'm an old dog but think I can still handle a few new tricks.

 

This is going to involve a lot of time and patience.
Do not think of this as a quick afternoon project.
This will likely take at least a week or two. Maybe even longer.

Go very slowly and carefully.
This is where things get tricky.

I'm not sure how to be clear that I cannot be held responsible if something goes awry. I'll offer what I can though and do my best to help out.

OK. With that out of the way I'll get the link and add it to this post.

edit: The document was in a different thread.
I've made a copy of it available via my web site.
Hymotion balance procedure from A123 via EV Powers site | EV Powers

 

Thanks and consider your liability waver signed. I have lots of patience and a strong work bench. I had found the "Hymotion Balance Procedure" on the other thread. I thinking I understand the procedure. I have high voltage gloves and several multimeters but I'm now thinking about getting a Fluke. Are there any better?


Please address these two questions:

1) I don't have the charger. Would you give me a brand and part # for a charger?

2) When (or if) I pull the L5 out of the Prius, will the car still be drive-able?


My motto, that I've pulled from several scholarly sources over the decades:

It's always something and if it ain't one thing, it's another. It's never easy and always takes longer than I think, and I do it better because I do it twice.

Cheers,

John

 

Thanks for the waiver. Whew.

I like your frame of mind that it will take longer than you think. This is not a process you want to hurry.

A Fluke meter would be fine.

The Prius will still be drivable without the Hymotion system in it.

As far as chargers... I tend to use a project as an excuse to buy new tools. And I like chargers. I probably own a dozen of them.

A 0-30vdc bench power supply will give you the accuracy needed for this project plus have the flexibility for other uses in the future. Amperage 0-2amps or so. The specs for voltage and amps could vary a bit.

 

You can drive the Prius with the pack out, but install that extra jumper plug that's back there before attempting to start the car! The jumper must be installed after removal of the pack, or the CAN bus will be non-functional. Plug it in where you unplugged the pack, and all will be fine.

 

Thanks guys,

I just ordered 0-30 VDC 0-5 AMP power supply. I also have that little Lambda 0-16 VDC 0-4AMP. And during sunny days one of my 48V 230Watt PV panels is not connected to the grid so I could play with that power with a rheostat ... maybe ;<). I think I'll keep using my old Beckman Industrial multimeter and pass on the Fluke for now.

Not sure when I'll get to it. I have an "I" beam gantry built in my small shop but no shop crane. The 4th July sales are on so I might get one this weekend.

I left it plugged in last night and with a charger also on the 12v battery. This AM the LED flashed the code all the way into work, about 18 miles. So it's at least talking to us more now.

 

The Lambda is probably plenty of supply for the job, but 30 Volts is nice to have. Stop plugging the pack in. It won't make any difference, no cells are going to get any charge until the low cell is brought back up manually. From your description of the (apparently) intermittent LED, you may have a harness problem somewhere too. I would try and find the spot where you can turn that on and off so you can pinpoint the issue and repair it. OR, maybe the 12V battery is getting low? You'll want to get to the bottom of that, whatever the cause.

If you don't already have it, dig around a bit for the A123 Battery Handling Guide. It's a great primer on this stuff generally.