Inverter Coolant Pump takes a dive

Mine has been making odd noises in winter for at least 1 1/2 winters now. Still working though. Wonder if I should order a replacement and hold onto it just in case...then I can take to the dealer and have them install it when it does fail?

 

Nahh. Whatever warranty the replacement comes with would probably expire before it got installed.

 

Well my inverter water pump just died on my 2004. Reading this board is like looking into the future... I can see what will go wrong with my car.

I was driving on the freeway going uphill when a bunch of lights came on. I had the Red '!' Master warning light, the solid yellow brake warning light, check engine light, and the MFD said "Problem". I took it to the dealership the next day (the yellow brake light went off the next day) and they pulled code P0A93 (Inverter Cooling System Performance Malfunction) from the car.

They replaced my inverter water pump (part #G9020-47031) and everything seems good now. Luckily I had the Toyota Extra Care warranty (paid for itself already) so that saved me a $400 bill.

I wonder if the ICE water pump is as faulty as the inverter pump? Or will it last a good long time? Well I guess you have to pay to have the cutting edge technology. Still love my Prius!

-Peter B

 

prberg, how many miles on yours?

 

Hi Peter,

I agree that PriusChat is great to help owners understand likely failures to be experienced by our very complex vehicles.

The engine coolant pump is mechanical and of traditional design. It would not be surprising for it to need replacement once your odometer reaches high-five digits or low-six digits. Usually there is some warning before a catastrophic failure, as coolant seepage can be seen from the weep hole. Look for pink powder (dried coolant) on the bottom of the pump.

 

My prius is at 72,000 miles. Glad to hear the engine pump is not prone to premature failure. I guess I will need to get more familiar with all the engine parts (I haven't had to think about it on this car so far) as my car gets more miles. The engine pump is the one that is behind the headlight, next to the fuses?

-peter

 

Hi Peter,

The pump that you are referring to is the inverter coolant pump that was just replaced. I was referring to the mechanical engine coolant pump which is mounted to the front of the engine (facing the passenger-side fender) and is powered by the serpentine drive belt. In addition to that pump, there are two electric pumps in the engine coolant loop.

One electric pump is located next to the coolant heat recovery canister, which runs only for a few seconds when the car starts up or shuts down, to move coolant from/to the coolant heat recovery canister. That pump can get noisy and owners have had it replaced for that reason. However I have not seen complaints that the pump has actually failed to operate. The pump can be seen when you remove the left front fender liner.

The other pump moves hot coolant to the heater core, to provide engine heat to the passenger cabin. I have not noticed owners complaining about that pump failing. You probably have to remove the cowl to see this pump, located near the firewall.

 

Thanks for the water pump lesson Patrick. I will have to peek under the hood so I can locate those pumps and make sure they are leak free. My electric pump that fills the coolant 'thermos' is a little noisy but doesn't really bother me. Good to hear that the noise isn't a sign of impending failure.

gotta love priuschat and it's helpful members.

-Peter

 

Hmm. Some clarifications for everyone.

The inverter pump is on the driver side, behind the headlight. Follow the tubing to the pink coolant tank to the left of the inverter. It's the pump that's responsible for the only audible noise when the car is in ready mode with the A/C off and no fans on.

The C/HS assembly (thermos bottle) pump is another electric pump, but it runs intermittently. It is also on the drivers side, but behind the tire. It (usually) only turns on when the engine is started (cold), or if the engine coolant is hotter than the thermos coolant (right after car is powered off.)

The ICE water pump is the _only_ belt driven component attached to the engine. It's on the passenger side. This is the everyday water pump found in every non air cooled engine, not very exciting .. It's connected to a belt, so follow that.

It is possible to see the inverter pump in action. Just shine a flashlight at the side of the water tank to the left of the inverter. The surface of the coolant shows a noticeable 'ripple' as the water is pumped.

Seeing this kind of failure is disturbing though, It is a risky single point of failure.

The walk away from this is that hopefully the $$$$ inverter won't cook itself, and based on what has been described so far, the software is indeed smart enough. Instead just a $165 pump goes bad. One more reason to have a scantool that does the inverter temperatures, of course, that's one more piece of info to monitor and be paranoid about..

 

My inverter pump just failed at 115K on my 2004. It cost me $535 for the repair since I am no longer under warranty. A dreaded red triangle was the means for detection.

Looks like a trend to me...

 

Just to add my inverter pump story, mine went out on Friday (08/29). I have an '04 with 51K miles. Only indication was the red triangle master alarm, CEL, and brake warning light. One thing I noticed after the failure is the regen braking stopped working. Also, upon restarting, the brake warning was not showing up.

I probably drove 15 miles after the failure until I could get it in to the dealership. Repairs were done pretty quickly for dropping in on a Saturday. No charge as I have the Platinum warranty. The cashier looked something up and said the cost would have been around $350.00 This is the first mechanical problem I have had with the car.

Dave

 

Count me in. Just got a call from the dealer. Luckily it was still under warranty.

Just under 40K miles 2005.

Allan

 

I just had my inverter pump replaced (two weeks ago) as well and now my milage is down by about 12 MPH! Same gas, same gas station, same driving conditions etc. Anyone else notice this issue after the inverter pump replacement?

 

i'm attaching a pdf of the tsb for general reference. this is not an unknown issue, as i said above DH replaced several of them when he was in the shop.

overheating is a very bad thing in general, so if you're getting warning lights and loss of power you need to get off the road asap.

 

The replacement of the inverter cooling pump should have zero impact on your mpg. If this continues I suggest you look for another cause, such as a nail in a tire causing underinflation.

 

The invertor coolant pump on my wife's 2004 Prius, with 45K miles, failed with DTC P0A93. Fortunately we have an extended warranty and the repair was fully covered. The cost for the pump, coolant, etc. was $130 and the labor was $204. The MIL and the check engine light came on while we were driving and there weren't any noises associated with the failure.

 

I got my '05 in December '04 and only have 23,600 miles on it. I was doing 62 on I-95 when the dashboard lit up like a Christmas tree. Thereafter, only the check engine light and master warning light (red triangle) stayed lit. I'm out of warranty (despite the low mileage), so they wanted $500 + labor. I pitched a fit and called Toyota (I just replaced the starter battery at the end of July for another $200). They "investigated" and told me that, due to my history with the dealership (bought our Sienna there, too, back in '04; had all the Prius maintenance done at the same place, etc.), customer loyalty, "amount of time out of warranty", yada yada yada, Toyota will pick up the tab this one time.

Thoughts?

 

Greetings to PriusChat miamiflash. My thoughts are that you got fleeced a bit on the 12 volt battery, and I'm glad that they came through for you this time. Please write a nice thank you letter to Toyota and send copies to the various administrative levels. This may make it a little easier for the next victim out of Prius warranty.

Other than that, we have seen enough of these pump failures now that the system certainly bears watching. It has been posted elsewhere how one looks at the coolant reservoir tank to confirm you have good pumping, yes?

Some time ago Patrick Wong suggested replacing this pump as preventative maintenance and this might be a very good thing to consider.

 

Since you posted on this string, I assume that your inverter coolant pump had failed. Is this assumption correct?

If so, then note TSB EG001-07 that Galaxee attached to a prior msg in this string. The applicable warranty is the powertrain warranty which is 5 years/60K miles. Therefore, if in fact the inverter coolant pump had failed, this should be covered under the warranty without need for you to request any special favors.

If you have a problem other than, or besides the inverter coolant pump, please advise the diagnosis and the DTC that were logged by your vehicle.

 

I just had the inverter pump replaced on my 07 at 29k after having the christmas tree dashboard lights. I hope this won't be a recurring thing.