2001 Prius inverter replacement

What did the shop identify as the root cause of the inverter failure, and how did they determine that?

 

The car is back at your place or the shop? Will you be doing the swap or just buying the part?

You might want to have them check the inverter coolant pump to see if it possibly got overheated. There have been some rare reports of coolant 'jelling' so make sure it is flowing.

I don't have my manual handy but P3125 also has a boat-load of sub-codes that point to specific interfaces being bad. We had a thread about this a couple of weeks ago:

http://priuschat.com/forums/generat...ius-my-2002-no-longer-starts.html#post1089365

GOOD LUCK!

Bob Wilson

 

Inverter mis-diagnosis is common on this vehicle. Do you know which three-digit code or codes the vehicle has in addition to P3125, and which TSBs were referenced?

 

From what I can tell of the over-the-counter scanners, your choices are either a Toyota service center or possibly the Autoenginuity scanner. Some of us are looking at what is available and the pickings are thin.

What happens is the error indication lights go out after three restarts but the codes remain in the controller memory. One thing about an intermittent problem, it will come back. You can check the inverter coolant pump yourself.

Raise the hood and then turn on the car to ignition. Facing the engine, the inverter coolant pump is located low, on the frame on the right. You should hear it running. Then check the inverter coolant reservoir to the left of the inverter. You should be able to see coolant flowing:

This photo ripped from "Prius Technical Stuff", "priusowners" folder showing "'01 coolant change", Feb. 3, 2004.

The recommended change interval is 50,000 miles and we've had reports of older coolant forming a jelly-like substance. In one case, requiring replacement of the inverter pump.

Bob Wilson

 

Since your car's problem is intermittent, it does sound like the root cause is overheating.

Bob already provided you with info to determine whether the inverter coolant pump is running. Notice in the photo that the front of the reservoir has a higher coolant level than the remainder of the reservoir. That shows the pump is running. See what your reservoir looks like when the car is either IG-ON or READY.

How frequently have you had the inverter coolant replaced? (30K miles is the service interval if you are using red Toyota Long Life Coolant; 50K miles if you are using pink Toyota Super LLC.)

 

No, there are commercial scanners (Vetronix, Snap-On, to name a couple) that will read the three-digit codes. The trick is to find someone who has the equipment and the knowledge.

If you pay to have your vehicle scanned, make sure you get a copy of the freeze frame associated with the three-digit code. It will be a list of several dozen parameters and values.

The freeze frame associated with P3125 will have maybe a dozen or so parameters and values, and won't help you figure out what is wrong with the car.

It's possible, but it's also possible that the criteria for setting the code hasn't repeated itself.

By the way, there are many causes of an intermittent P3125 code other than overheating. Until you get the three-digit code, the best anyone can do is make an educated guess.

 

I am new to this forum. I have a 2002 prius I just purchased with the same error code showing up in diagnostics. The car is running also. The Toyota dealer said it needs a new inverter and that there is possibly a main battery leak. Again, the car is running fine. It does have a tendency to get 48+ miles on highway and low to mid 30's in town driving. I will stand by this recent purchase and bite the bullet of whatever it takes to fix it, be it a salvaged inverter/battery pack if need be. Can you guys give me some advice on the possible direction to go? Rich

 

"Same code" meaning P3125? Do you know the three digit code, as well?

 

I have the same issue with codes p3125 and c1259, the dealer said it is the inverter, actually i recently spent 6400 dollars on replacing hybrid battery and transmission, now my car is in my drive way and i am looking for inverter in a junk yard.

 

The C1259 will go away when the ABS codes are cleared after correcting whatever's wrong with the hybrid system. That would be the P3125 and the "INF codes" that go with it.

Since a lot of work was recently done on the hybrid system, if it were me I'd be really curious to find out whether this current issue could be something iatrogenic, before starting to shop for another part.

-Chap

 

I understand the word in medical terms. Are you saying that the last place worked caused the problem? ie: The dealership? iatrogenic, really chappy, that is too much!:cheer2:

 

Really, all kidding aside, my sense is that there's an element of that in a lot of car problems. If you think about it, except for accidents, the most disturbance a car's systems ever see, and biggest chance of getting things messed up, happens in the shop (or under the shade tree). This is true no matter how good the person is who does the work.

In this car, the HV battery and tranny were recently replaced; the transaxle replacement in particular is very invasive work with lots of things having to be disconnected, moved out of the way, and reconnected later. At the age of our Gen Is it's possible for wiring connectors to be getting a bit marginal, and after disturbance and reconnection to be, well, differently marginal. Some problems of that nature could probably produce HV DTCs (I haven't looked up exactly what could be behind a P3125 and I didn't see the INF codes posted to help pin it down). The battery work is less involved but still disturbs the HV wiring, the main relays, and all the battery ECU connections.

I would consider the history of recent transaxle and battery replacement to be a strong reason to investigate whether the codes being seen now could be related to anything that was disturbed in that work, before concluding that the inverter itself must be bad.

-Chap

 

You are exactly right. I worked in Electronics for many years, both on the flightline and the bench. I always made a policy to find out who worked the problem last and what they did. Sometimes I found out it was ME! :cheer2:

 

I'm having some major problems right now and "jelling" in the inverter coolant reservoir is significant. I replaced the plugs (which were in good shape) after getting a series of "random misfire" codes and now it's cutting out with increasing frequency. Although I was using the car for months, I just purchased it and immediately started having problems. I routinely check fluids, but until recently, I only checked the inverter reservoir visually, through the transparent housing. I removed the hose and tried to flush out some of the jelled material, but it was quite significant.

Can I buy coolant flush and flush this system just like the regular cooling system or would that cause more harm to the inverter?

Starts fine. Operates fine (for a few miles) and then the brake light comes on and the accelerator quits while the motor revs. If I stop and re-start the car, it runs flawlessly for a few more miles.

There is "some" visible flow in the inverter coolant reservoir, but I'm sure it's restricted by the jelling.

Is this degree of jelling because of someone fixing the wrong (green) coolant and what can I do about it? Can it be dissolved and flushed from the Inverter system? Thanks.

 

Is there any chance you could post some pictures of the jelling? Also could you please update your location?

 

OMG green?? no no no no..

You can only use Toyota long life coolant... I can't even imagine what the other stuff did/does. You can flush it with a hose, the problem is with this car it is very very hard to get all the air out. There are about a dozen paths for the coolant and a thermos reservoir tank and a three way diverter then some coolant through the inverter and inverter "radiator" section.

 

Gen I here.