inverter testing and replacement

[lmahaj]

Can anyone inform of any testing procedures (links or a good manual) for an inverter and/or inverter pump? Voltages? Resistances? etc? How often does the pump switch on? Thanks....

[Patrick Wong]

Originally Posted by lmahaj

Can anyone inform of any testing procedures (links or a good manual) for an inverter and/or inverter pump? Voltages? Resistances? etc? How often does the pump switch on? Thanks....

I strongly suggest that you either purchase the Toyota paper repair manuals for your vehicle (which are available by ordering through your dealer's parts dept), or invest some money and time downloading appropriate repair manual files at the techinfo.toyota.com subscription website.

The inverter pump runs constantly when the car is IG-ON or READY. The easiest way to test the pump is to listen for it running. It is located near the driver's side headlight assembly. If the pump is removed, apply 12VDC to the terminals for a brief period of time (since no fluid is in the system, we don't want to overheat the pump), to confirm that the motor is running.

Regarding the inverter, evidence that it has failed is provided when appropriate DTC are logged by the hybrid vehicle ECU. Other than checking for high voltage leaks to ground, I do not believe that there are any other tests that the repair manual suggests for the inverter. The inverter is not a field-repairable assembly; the repair philosophy is a whole-unit swap.

[_echo]

Other non-toyota links to consider include:
The set of ORNL reports that came out in ~2005. Be careful with these, It appears that they might have reversed the polarities on some parts. But hey, your tax dollars paid for them, might as well take advantage of their research!

EE times also did a teardown awhile back. (I only have a paper copy, but they did it at Embedded systems conference in ~2006)

Hobbit's page has some excellent teardown info.

I'm probably missing a whole bunch of other sites.. But those are some unofficial, but _highly_ trusted ones. I highly recommend the toyota service manual, as this has the 'official' stuff...

[GinnyErns]

Am curious as to why you are asking how to check the inverter. Isn't it part of the hybrid system and therefore covered under the 8 yr/100,000 mi warranty? if so why don't you have the dealer check for you. I am a new prius owner and am learning the high price tag of do it your self jobs on these cars.......take a look at my thread in this Technic. Discuss.........."I blew up my inverter"......also if you find that your inverter did go bad I would like to know as I have been lead to believe they don't go bad....we just blow them up..................please let me know what you find out by posting on my thread or here....I will watch to see what info you get....thanks Ginny

[bwilson4web]

Originally Posted by GinnyErns

Am curious as to why you are asking how to check the inverter. Isn't it part of the hybrid system and therefore covered under the 8 yr/100,000 mi warranty? ...

His Prius is an 2003 as is mine. I passed through 100,000 miles just at the end of last year. I have no further warranty coverage (and am kinda glad about it.)

Bob Wilson

[GinnyErns]

Originally Posted by Patrick Wong

I strongly suggest that you either purchase the Toyota paper repair manuals for your vehicle (which are available by ordering through your dealer's parts dept), or invest some money and time downloading appropriate repair manual files at the techinfo.toyota.com subscription website.

The inverter pump runs constantly when the car is IG-ON or READY. The easiest way to test the pump is to listen for it running. It is located near the driver's side headlight assembly. If the pump is removed, apply 12VDC to the terminals for a brief period of time (since no fluid is in the system, we don't want to overheat the pump), to confirm that the motor is running.

Regarding the inverter, evidence that it has failed is provided when appropriate DTC are logged by the hybrid vehicle ECU. Other than checking for high voltage leaks to ground, I do not believe that there are any other tests that the repair manual suggests for the inverter. The inverter is not a field-repairable assembly; the repair philosophy is a whole-unit swap.

PATRICK: need to get educated on this part too. What would be the symptom if there was a high voltage leak to ground? Would the car stall or quit running. Thought the only way the inverter went bad was if jumped with wrong polarity??????
Thanks, Ginny
from "I killed my inverter???"

[Patrick Wong]

Originally Posted by GinnyErns

PATRICK: need to get educated on this part too. What would be the symptom if there was a high voltage leak to ground? Would the car stall or quit running. Thought the only way the inverter went bad was if jumped with wrong polarity??????
Thanks, Ginny
from "I killed my inverter???"

Hi Ginny,

The Prius inverter will occasionally fail. Usually this is because the inverter coolant pump stops running which causes the electronics to overheat. Most of the time, once a new pump is installed, all is well. However on occasion the inverter will be fried as a result of overheating. By and large, I would say that Toyota is unusually generous in covering such incidents under the hybrid system warranty.

The Prius high voltage system is set up so that neither the negative or positive side is grounded for safety reasons. The battery ECU will monitor the status of the high voltage line and generate DTC P0AA6 if it detects any leakage to ground.

The DTC will not prevent the car from running when it first appears. However once the car is shut down, it will refuse to restart. When the DTC is logged, the master warning light and hybrid vehicle icon should turn on.

[bwilson4web]

Hi Ginny,

Originally Posted by GinnyErns

... What would be the symptom if there was a high voltage leak to ground? Would the car stall or quit running. ...

Yes, it is a safety thing. The battery high voltage and inverter outputs that drive MG1 and MG2 have a 'ground fault' detection circuit and if it ever falls below 10 megaohms, it not only throws an error code and master alarm, it shuts down the whole high voltage system. The error code is "P3009" in the NHW11 models.

This is a safety feature so if the battery power cables that run under the car; a water or electrolyte leak; or anything else compromise the high voltage systems, the car fails rather than risk human life. We can always replace a car.

Bob Wilson

[Patrick Wong]

Originally Posted by bwilson4web

...The battery high voltage and inverter outputs that drive MG1 and MG2 have a 'ground fault' detection circuit and if it ever falls below 10 megaohms, it not only throws an error code and master alarm, it shuts down the whole high voltage system. The error code is "P3009" in the NHW11 models.

Hi Bob,

I know of a Yahoo poster who continued to drive her Classic although DTC P3009 appeared.

With 2G, the equivalent DTC is P0AA6. When this DTC appears, the car can continue to be driven; however once it is IG-OFF, then it will refuse to restart.

[bwilson4web]

Originally Posted by Patrick Wong

...
I know of a Yahoo poster who continued to drive her Classic although DTC P3009 appeared.

Wow! Another reason to prefer the G1! <grins>

Originally Posted by Patrick Wong

... With 2G, the equivalent DTC is P0AA6. When this DTC appears, the car can continue to be driven; however once it is IG-OFF, then it will refuse to restart.

Owch!

Bob Wilson