Help with sick Prius p3100 p3125 c1259

hmmm. the mg2 temp is not higher than the mg1 so thats a good sign. also you might wanna check with california state law on the warranty. correct me if im wrong but isnt the hybrid system covered up to 15 years 150ooo miles. or is that just the battery. i would see if someone at these garages has a good inverter laying around and see if they will let you hook it up to your prius and see if it works.

 

replacing an mg2 is dooable at home. your dont have to completely drop the trans out. just get the trans down far enough(yes its still hooked to the engine) to get the cover off from the drivers side wheel well. and you can access mg2 from there, pull the old windings out and install your new one. i think new ones from toyota are 1k. i know there are guys that have done this in 8 hrs or less.

 

When I've seen P3100/175 and P3125/287 the Toyota docs point to the inverter, but I'm sorry to say your tranny is toast. If you don't have P3009, it's probably not MG2 (use a meg ohm meter to confirm), it's likely something else inside the tranny.

You can try swapping a known good inverter, but you'll probably see the same codes.

If it was my car I would swap the entire tranny.

 

We can't use the ICE > MG1 > MG2 test because the car can not drive enough to generate the heat. I suspect a sample of the transmission oil will be more than enough to confirm the burnt MG2 hypothesis.

Swapping the transmission is a pain but more than a few have been done it over the years. It is a heavy part so care must be taken.

Bob Wilson

 

You might head over to the YahooGroup, "Prius Technical Stuff" as Cor has a bad engine, probably good transaxle, on a pallet in California . . . LA?
Yahoo! Groups

You might join the group and see what can be worked out.

Bob Wilson

 

The Classic Prius warranty has expired by now. The hybrid system warranty is for 8 years, 100K miles regardless of US state. The transaxle is covered for 5 years/60K miles, again regardless of US state.

The reason the warranty terms are longer for 2G in CA (and some other states adopting CA emissions regs) is because 2G is certified as AT-PZEV compliant.

 

Hi capriusfan,

For P3100 - 175, I suggest to monitor Motor Current V and W while creeping slowly at < 5 mph. Your screen shot for HV ECU show 0.00 A which is normal when not moving. If it is moving and still shows 0.00 A, you should check the MG2 current sensor. There is a similar problem to yours but it is the MG1 current sensor, pls refer to this thread.

Vincent

 

Your suspicion is right: the brake ECU has to coordinate with the HV ECU for regen braking to work, and C1259 is a generic code the brake ECU will log whenever the HV ECU tells it something's not right. To find out *what's* not right, you just have to look at the HV ECU codes, as you've been doing. Once that's fixed you can clear the C1259 in the brake box (or it will probably go away after a few ig cycles on its own).

-Chap

 

Chap is correct, C1259 shows up as "collateral damage" when other codes are present. I usually ignore C1259 and fix the other codes, C1259 should go away on it's own.

 

I remember that one because the failed part was sent to me. I could not find any overt evidence of a failure mode and eventually tossed it. Interesting development.

Bob Wilson

 

Cannibalize a salvage inverter where something else broke?

-Chap

 

Hi capriusfan,
I had a sick 2002 (bad knock in the engine as well as bad HV battery) and replaced both with good used ones. Since I could get a complete engine & transaxle assembly, I replaced the whole deal, so the bad engine with the good transaxle still attached is sitting in my garage, waiting until I get around to do a post-mortem on the engine and sell off any usable parts. I also have a complete inverter that came with the deal. If you want to get rid of the car, I have a colleague looking for a cheap Prius, some work on it is no problem.

 

Capriusfan, if you must swap the inverter try and borrow a known good one somehow rather than buy one. Or buy one from a vendor that will let you return it...just in case.

In fact, I'll bet you a beer swapping the invertor won't solve your problem. BTDT.

 

Hi capriusfan,
I found out that I was accidentally using an old account here on Prius chat (I was unaware that I had already registered once as "Cor" and thus that is the same person as EV_Cor.... As you might have noticed, I do have an inverter that I can sell (or borrow if you ship it back) and a complete transaxle that you can also buy or borrow - or if you just want to unload the complete car, I will have to convince my wife that it is a good idea, so I will need some pics of how it looks ;-)

 

I need to replace the HV ECU on 2002 Prius, but unable to find it. Can any one tell me where is the HV ECU located. Thanks

 

Lift the carpet on the passenger side footwell and you should be able to find the hybrid vehicle ECU.