DIY: Inverter Pump Replacement (10-15 Prius)

Thanks for posting about your experience.

How about a photo of the original vs. Aisin replacement coolant pump? Any differences in appearance?
What was the Aisin pump price from RockAuto?

 

I found your notes helpful as I just replaced my Inverter Cooling Pump on my 2010 Prius.

4 hours. I would estimate 2 hours to do it again - but such is the first time you do something.

Helps (almost impossible without) to have a helper for certain things.

After removing inverter mounting bolts and blocking up the inverter (to the rear) You need to remove the one bolt facing up from above and the hose that goes to the pump outlet (Port facing straight up - or axially).
Getting the factory el cheapo hose clamps off can be a major challenge. Large needle nose vice grips are very helpful.
I found it easier with the pump loose so I could vary the angle on the hose clamp. (Took out all 3 bolts. One from above, two from below).

You will need to bend the bracket from below to get the pump out the bottom. You'll need to compress and move the radiator hose as well.
It's tight but doable. Get the vehicle as high as practical. I used ramps and it was tight but doable.

Connector to pump maybe quite stubborn to get off (plastic hardened). I took the next connector back off and left pigtail on pump.
Much easier to do on bench once I get pump out.

Start reinstall by putting in the single bolt from above to locate the pump. Do not tighten all the way down.

The bracket that mounts to pump and provides a nut for the two bolts that mount from the bottom is a real bear.
If I had to do it over, I would have tied wrapped it to the pump, mounted the pump, and then removed each tie wrap in turn and replaced with bolts.

I fiddled with the bracket for 90 minutes before using a magnet to hold it in place from above (held by a helper). I could then hold the bracket down from below as I threaded bolts into the bracket. What a goofy design. I think Toyota hired some ex-GM Engine Engineer for this one

Easier than removing the Inverter ? Probably a wash the first time. If I ever had to do it again, this method will be faster.

Hope this helps,
Boomer

 

I had some noise which sounded as if the inverter pump was going bad. Purchased the Aisin from Rock Auto, as well as an Aisin engine water pump, as the car has 160k. Installed both today using the 2x4 inverter tilt up method, but missed connecting the inverter water pump bulkhead connector. Tried to start the car, but was presented with the red triangle of death. Turned the car off, and realized that there was a pump connection issue. Unfortuantely, after connecting the bulkhead connector, I am still getting the red triangle. Torque OBD app indicates Inverter rpm at 500 (not the normal 3350 rpm). Anyone ever run into this? If a P1314A code is thrown for a missing pump, will the ECU stay in hybrid failure mode until the code is reset? I am also am considering the idea that I have a defective new pump.

 

Was driving my 2010 Prius IV in town when I got the check engine light, yellow triangle, ABS light, and "Check Hybrid System" message. The car went into limp mode so I was able to get to my friend's house. Scanned the codes and got P0A93, P0A94. Did some research and was pretty sure it was the Inverter coolant pump. So I bought the Aisin from Rock Auto and went about replacing. Man, this was a PITA! I did the "tilt the inverter back" method and was able to get the old pump out from the top by myself. As noted previously, the biggest difficulty with this job is getting the top bracket back on once the new pump is in place. I tried the telescoping magnet with no luck. Then my friend made the brilliant suggestion to lash the bracket to the pump using rubber bands prior to putting the pump in place. I was able to do that and get the top bolt secured. Then I was able to get one of the bottom bolts started into the bracket being held to the pump via rubberband. Once one bottom bolt was in place, I cut the rubberbands and was able to get the second bottom bolt in place. Unfortunately, once I hooked everything back up, the P0A93 and 94 did not clear. The old pump seemed to run fine when 12 volts applied but had a bad bearing rattle when it spooled down. So, probably a good thing I replaced it. I tried clearing the codes with my ODB (Bluedriver) app but they came back immediately. Not sure if there is anything else I can do at this point other than take it to a shop. Any suggestions would be great.

 

Did the new pump run despite codes? Do you see turbulence in the reservoir?

How many miles?

SM-A536V ?