inverter pump failure highlights moronic display design

Wish I saw that link earlier.

Odd that "Toyota" undercuts its dealers parts sales that much - the Amazon price is ~$90 less than the Pasadena (CA) Toyota dealer quoted. The link currently says "4 in stock, more on the way". Since there seems to be a shortage of the things at the moment it isn't going to surprise me much if a couple of days from now it says "none in stock, more on the way" and stays that way for a month.

I believe you that the OEM unit is probably better. However, since the Dorman will be delivered today I'm going to install it. Hopefully it will last for a while. At least I know now to check that that pump is working once in a while, since the car can apparently run most of the time without it and only throws a CEL on a very hot day under heavy load. I drove back and forth to work yesterday after clearing the CEL and even though it was a 90F day the CEL did not relight. Apparently 7.5 miles on surface streets wasn't enough to overheat anything.

 

You are right, pump failure does not cause a CEL. (It really should though.) Driving on the highway at 100F without the inverter pump working raised the inverter temp high enough to throw a CEL. Cleared it the next day and it has not returned in two more days of street driving mid 90's and mid 80's. Hard to say when the pump failed - it could have been month ago.

 

The only code set was P0A93. When it first happened it looked just like the picture at the top of this thread:

Warning lights - What do they mean? | PriusChat

This thread also reports the same set of lights for an inverter pump failure

Red triangle, check engine, and brake warning lights. No codes | PriusChat

The brake light went away while the car was shut down. I don't recall now if the CEL went away by itself or not before the codes were cleared. In any case since clearing them nothing has lit up again. So there is no reason to think anything is wrong other than the failed inverter pump.

 

Replaced the pump yesterday and it is working. Details (if they differ much from other descriptions) put in an existing inverter pump thread here:

How to Replace the Inverter Coolant Pump | Page 11 | PriusChat

 

Apparently you are correct. The red triangle of death appeared and P0A93 is back. Presumably the Dorman pump just crapped out. When the car is on there is an uh-uh-uh sound from under the inverter. The coolant level in the tank next to the inverter is a bit higher than it was, and it is pulsing rather than swirling. I think the rotor in the pump is probably almost but not quite stuck, so it wiggles back and forth a little, but does not turn. This time though the inverter temperature when I got it home was only 142 for MG1 and MG2, so not all that hot. Not quite sure how it knows that the pump isn't working at those temperatures, last time it was much hotter.

Dealer has the OEM ones in stock this time, $40 more than the Amazon one, but I can pick it up now and put it in once the car cools off.

Will deal with the Dornan "warranty" later.

 

After it cooled down the car was disassembled to the point where I could reach the pump. Turned the car back on - and it was working fine. The pump was whirring normally, normal turbulence was present in the tank, and the tank level was back down where it would normally be. It was right up at the top when it was having problems - heat expansion of the coolant? The funny sound wasn't present. I do see a slight pink crust around the bleed screw, not sure if that means it was leaking after the pump install, or that was just the little bit of fluid that dripped during the install and then dried out. Triangle was still lit.

Attached is a zip of an mp3 recording made earlier. It starts with my son and I talking back and forth and the uh-uh-uh sound comes on for the last few seconds. Anybody heard that sound before?

Just before the triangle appeared we sat for 15 minutes at a toxic waste drop off. It was hot and the A/C was on the whole time. Car was in drive as we inched along. The light did not come on then. It came on 10s after accelerating onto a highway once we were done with the task.

I will check for subcodes. Maybe I will try bleeding it again. If some air got in it might have caused the pump to stall.

 

Where is it? Any idea what the OEM part number is? I wasn't aware that there were any valves in the inverter coolant loop. Are you referring to the valve for code P1121? That code was not set, but perhaps that valve has not quite reached that point.

Ran techstream again and theP0A93 subcode was 346. Reset the error codes and they stayed off for the short time I left the car running. No big surprise there, the car ran for a week with a known failed inverter pump when driven on only short trips with no red triangle or CEL light.

 

Continuing this in what seems to be the main inverter pump thread:

How to Replace the Inverter Coolant Pump | PriusChat