Inverter pump failure- aftermath?

arniesalsared · 10-23-2009, 02:22 PM

Hi all

Posted this in the Gen Tech section possibly wrong place so, again-

We have three GenII Pri's in the family. The three located in Arizona have had Inverter pump failures each during a peak heat month.
All have been replaced on warranty, mileage from 35k to 85k with assurance that no long term damage has occurred.

My '04 has 85k and it's failure occurred a few months ago. A few weeks ago noticed that one tank average had dropped from 50 +/- 1 to 43 +/- 1 MPG.

Checked tire pressure, oil level, brake drag, DTC's etc and all good.

Could the inverter semi-conductors be going bad with no DTC's?
What else could it be??

Patrick Wong · 10-23-2009, 05:32 PM

Usually a semiconductor acts in a binary function: it either works or it doesn't. So if your car becomes READY and there are no warning lights, I would look elsewhere for the reason for an mpg decline.

Also, having mpg low with one tank is not enough to be worried. Who knows, you might have been shortchanged at the pump, the energy content of the fuel might be below normal, etc.

richard schumacher · 10-23-2009, 07:42 PM

[mis-information deleted]

tochatihu · 10-23-2009, 08:44 PM

Does Phoenix switch to a winter fuel blend right about now?

ibmindless · 10-24-2009, 12:32 AM

What was that news I recently heard? Something about the gas expanding in underground tanks when temps outside become high, thereby making pumps indicate more fuel was pumped than what actually flowed into tank.

hobbit · 10-24-2009, 12:45 AM

Even if the little processors on the inverter electronics module
are flash-based, I seriously doubt a dealer has any way to reload
them. Main ECUs, yes, something as embedded as that, no. I
spotted nothing that looks like a programming interface on the
control board.
.
_H*

HTMLSpinnr · 10-25-2009, 12:29 AM

Not to support anecdotal theories, but I kinda noticed the same thing after mine went at 101k miles. MPG was never quite the same after. I kinda thought it was the overpriced injector cleaner they put through as well.

2009Prius · 10-27-2009, 01:18 PM

I think it is possible for transistors to degrade after operating at too high temperatures. The dopants could diffuse away from where they are supposed to be.

arniesalsared · 11-06-2009, 11:47 AM

The '04 has now had at least 4 tanks of fuel and still 45 or so average on MFD and by tank calculation.

Slightly better due to the cooler weather.
10 % MPG reduction is not worth a huge effort but it's got to be related to the pump change.

Now it's comparable to my wife's '06 fuel efficiency.

10-23-2009, 02:22 PM	#1
arniesalsared Member Join Date: Aug 2004 Location: Phoenix, AZ Posts: 39 My Car: 2004 Prius Model: Package: #8 Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	Inverter pump failure- aftermath? Hi all Posted this in the Gen Tech section possibly wrong place so, again- We have three GenII Pri's in the family. The three located in Arizona have had Inverter pump failures each during a peak heat month. All have been replaced on warranty, mileage from 35k to 85k with assurance that no long term damage has occurred. My '04 has 85k and it's failure occurred a few months ago. A few weeks ago noticed that one tank average had dropped from 50 +/- 1 to 43 +/- 1 MPG. Checked tire pressure, oil level, brake drag, DTC's etc and all good. Could the inverter semi-conductors be going bad with no DTC's? What else could it be?? __________________ '04 Salsa Red EV CAN-view, Pioneer Nav, Backup Cam Approx 70,000 miles and close to 50 MPG avg. Wife has '06 w/35,000 miles and only gets 44 MPG! Two daughters have 07's getting 50 MPG.

10-23-2009, 05:32 PM	#2
Patrick Wong DIY Enthusiast Join Date: Mar 2008 Location: Green Valley, AZ Posts: 4,053 My Car: 2004 Prius Model: N/A Package: #9 Thanks: 21 Thanked 213 Times in 184 Posts Friends: 44	Re: Inverter pump failure- aftermath? Usually a semiconductor acts in a binary function: it either works or it doesn't. So if your car becomes READY and there are no warning lights, I would look elsewhere for the reason for an mpg decline. Also, having mpg low with one tank is not enough to be worried. Who knows, you might have been shortchanged at the pump, the energy content of the fuel might be below normal, etc.

10-23-2009, 07:42 PM	#3
richard schumacher Destination: Eschaton Join Date: Mar 2004 Location: United States Posts: 5,512 My Car: 2004 Prius Model: N/A Package: #6 Thanks: 99 Thanked 93 Times in 66 Posts Friends: 0	Re: Inverter pump failure- aftermath? [mis-information deleted] Last edited by richard schumacher; 10-24-2009 at 12:25 PM.

10-23-2009, 08:44 PM	#4
tochatihu Senior Member Join Date: Apr 2004 Location: Kunming Yunnan China Posts: 2,411 My Car: 2001 Prius Model: Package: Pioneer #1 Thanks: 1 Thanked 39 Times in 39 Posts Friends: 14	Re: Inverter pump failure- aftermath? Does Phoenix switch to a winter fuel blend right about now?

10-24-2009, 12:32 AM	#5
ibmindless Senior Member Join Date: Apr 2007 Posts: 147 My Car: 2007 Prius Model: Package: #6 Touring Thanks: 3 Thanked 12 Times in 10 Posts Friends: 1	Re: Inverter pump failure- aftermath? What was that news I recently heard? Something about the gas expanding in underground tanks when temps outside become high, thereby making pumps indicate more fuel was pumped than what actually flowed into tank.

10-24-2009, 12:45 AM	#6
hobbit Senior Member Join Date: Mar 2005 Location: Bahstahn Posts: 3,625 My Car: Model: Package: Thanks: 0 Thanked 216 Times in 118 Posts Friends: 0	Re: Inverter pump failure- aftermath? Even if the little processors on the inverter electronics module are flash-based, I seriously doubt a dealer has any way to reload them. Main ECUs, yes, something as embedded as that, no. I spotted nothing that looks like a programming interface on the control board. . _H*

10-25-2009, 12:29 AM	#7
HTMLSpinnr Gen III Forums Moderator Join Date: Dec 2003 Location: Surprise, AZ (Phoenix) Posts: 4,074 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 216 Thanked 437 Times in 196 Posts Friends: 18	Re: Inverter pump failure- aftermath? Not to support anecdotal theories, but I kinda noticed the same thing after mine went at 101k miles. MPG was never quite the same after. I kinda thought it was the overpriced injector cleaner they put through as well.

10-27-2009, 01:18 PM	#8
2009Prius Senior Member Join Date: Mar 2009 Location: USA Posts: 438 My Car: 2009 Prius Model: Package: #2 Thanks: 246 Thanked 20 Times in 19 Posts Friends: 19	Re: Inverter pump failure- aftermath? I think it is possible for transistors to degrade after operating at too high temperatures. The dopants could diffuse away from where they are supposed to be.

11-06-2009, 11:47 AM	#9
arniesalsared Member Join Date: Aug 2004 Location: Phoenix, AZ Posts: 39 My Car: 2004 Prius Model: Package: #8 Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	Re: Inverter pump failure- aftermath? The '04 has now had at least 4 tanks of fuel and still 45 or so average on MFD and by tank calculation. Slightly better due to the cooler weather. 10 % MPG reduction is not worth a huge effort but it's got to be related to the pump change. Now it's comparable to my wife's '06 fuel efficiency.

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