P0A93 code

Do you see any turbulence in the coolant reservoir with the car in IG-On mode (2 presses of the Power button with your foot off the brake)? Where did you source your pump? There have been reports of defective or substandard pumps marketed deceptively as OEM.

 

It takes awhile for the inverter to heat up to the point where damage will occur. If the ambient temperature is low or moderate, you should be Ok for a few miles. If the code does not come up immediately upon starting the car, the pump is probably functional to some degree. There is also a possibility that you may have some blockage in the coolant passages of the inverter or the radiator that is impeding the flow, and the pump itself is fine. If you get the red triangle at any point, I believe you should stop driving the car and let the inverter cool before continuing.

 

Did you bleed the inverter loop after replacing the pump?

Are you sure the two hoses are attached correctly (ie, not swapped)?

Are you sure that the pump's electrical connector is seated?

Did you check the AM2 fuse (which the first failed pump may have caused to blow)?

Does "still getting the code" mean that you cleared the old one and it returned? Since you swapped the battery that would normally clear it, but you might have done that before changing the pump and reset it in a test drive.

Are you getting the red triangle or just the code? In normal city driving with a working inverter pump I find that the inverter is not even warm to the touch after a 10 mile drive (no A/C running). On the flip side, if the pump is out the car will throw the red triangle in highway driving in less than a mile, at least if it is warm out. When that happens the inverter will be too hot to touch.

 

Chinese copy. Probably about as high quality as the counterfeit Denso spark plugs.

Also keep in mind the P0A93 has 2 subcodes. One subcode designates the probable failure as being the "water pump system malfunction" circuit and the other subcode designates the probable failure as the "electric cooling fan system malfunction" circuit.

 

How familiar is the mechanic with the Prius? If he/she has done the job before, they should have routinely done some of the things we are asking you to do. Hopefully they would also have Techstream (Toyota's official software for diagnosis), which would reveal the subcode.

It sounds like the red triangle does not come on immediately, which means that you should be able to drive the car a short distance, but 30 miles is probably too far. Turning on the heat does nothing to alleviate the overheating of the inverter, the heater is on the Internal Combustion Engine's cooling loop, which is separate from the one for the inverter.

Changing the inverter pump is not that difficult, even for a novice mechanic, but if you are unwilling to give it a shot, it is probably not worth your while to purchase Techstream and the related equipment for it, so I believe the best advice would be to take it to a Toyota dealer and get a proper diagnosis (i.e. subcode). To have them diagnose and fix the problem, you should probably pay no more than $400 to $500. A knowledgeable independent mechanic (if you can find one) with Techstream or similar software to read detailed codes would probably charge about half of that.

 

Directly in front of the inverter will be what looks like a brake bleeder fitting. It normally has a black rubber cap on it. Connect a small rubber hose to it. Remove the cap from the inverter reservoir and put the other end of the hose into the reservoir opening. Press the car power button 2x with your foot off the brake. This will put the car into 'IG-ON' mode and the Inverter Cooling Water Pump should run. If it isn't, then you found the problem. Assuming it's running, loosen the 'brake bleeder fitting' and it should start flowing fluid/air/bubbles. let it go for a minute and there should be just a solid stream of coolant. If you're still seeing air pockets pass through, keep letting it flow. Once you're confident all the bubbles are out, tighten the fitting, remove the hose, replace the caps and you're done.

 

Either the pump is not running or it is air bound.
Are you able to touch the pump housing to see if it's vibrating?
Normally, the pumps get a bit noisy when air is in the system and then quiet down when they're moving only liquid.

Also, the is an electrical plug (one wire in and one wire out) that is located just above and to the passenger side of the fuse box. That plug is in line with the pump power connector. I have seen where the plug gets disconnected due to the pump shorting out, and then when the pump gets replaced, the plug never gets reconnected. You should verify that plug is actually connected.

Look at the photos in this thread, it will show the connector, labelled in post 4.

Total Shut Down- No Warning Lights, Please Help! | PriusChat

 

Meeces?

 

ding-ding...we have a winner!!!!!

That wire is in line with that connector. That connector is in the power source line for the inverter cooling water pump. Broken wire=no power to pump.

Fix wire=fix pump problem.

Well Done!!

 

Hey guys I’m having the same issue, I just swapped out my inverter pump and did not see any flow as some videos have stated when a pump is operating correctly. I ordered from parts geek and they had good reviews on the pump. My guess is that the fuse may have blown but I don’t for the life of me know which fuse it is. Can you guys please assist? Thanks in advanced

 

AM2 is the fuse you want. It is the second one down (15 A) on the right in your image. Check it for continuity with an ohmmeter.

 

Is it this one I circled?

 

Yup.