P0A93 Concerns

Which pump are you running manually? The error points to the electronic inverter pump, there shouldn't be a manual way to run it.

 

Maybe you have a bad relay?

 

Just had a co-worker with very similar symptoms last week. Also a 2008 with about 180k miles. After about 15-20 minutes of driving, a P0A93. She had it taken to dealer and they wanted $670 to replace the inverter pump. That was not an option for her. They cleared the codes and she drove it home. Coded again on the way home. Got in contact with me through a mutual friend. Sent me the dealer report via phone message. Got a pump through AutoZone for $157 total out the door (high $, I know, but no other option at the time) and went to her house the next day. Hooked up techstream, knocked out a health check and spent about 20 minutes showing her some things on TS. Same info as dealer report provided. Physical testing? .... All indications when cold were that the pump was running and operating. After speaking to her about the pump recall, she called the previous owner (mom) and found out that it had been done a handful of years and many miles ago. Snatched out the driver headlight, clamped off the hoses, swapped the pump, bled out the trapped air and added about 4 ounces of fluid to top it off. Bunches of ripples in the reservoir. Techstreamed it again to clear all codes. Seeing as I was never there to diagnose the problem when it happened, and I'm confident any pump can have an intermittent failure mode, it made sense to me to believe what the car was telling me. It's been 6 days since the pump swap. No codes. Problem solved? Most likely. It was 90 minutes from the time I left my house until I was back home having a




Get in the car. No foot on brake. Press start button wait a couple seconds and press it one more time. The pump should run and you should have flow in the reservoir. Her pump ran and had flow. After swapping the pump, it had noticeably more flow. If the pump isn't running, then you could very well have a bad relay, especially if the pump runs when you bypass the relay. Other than that, sometimes you just need to believe what the car is telling you.

 

I'm not familiar with this method. On inverter pump swaps, I just connect a rubber tube to the bleeder valve and put the other end into the reservoir. Press the start button twice to put car in accessory mode and the pump runs. Air bubbles and fluid pass through the tube into the reservoir and I add fluid as needed. Works just like a brake caliper bleeder valve.

 

Themsah,

Also want to mention, when you do the pump, just use clamps on the hoses instead of draining the system. Makes life much easier. Clamps are available at autozone (3 sizes in a package) for about 15 bucks, or about 10 bucks for same thing at harbor freight.

 

Maybe a blockage in the inverter? There have been a couple of posts very recently where blowing air through the inverter cleared a blockage caused by slime/jellified coolant.

 

The first thing that pops in my head is: is the "jumped" relay powering the inverter pump or something else? like maybe the pump that moves coolant between the engine and storage tank?

 

Are there any gaskets that should be replaced while putting in the new pump? 2009 186k with a returning P0A93 code going to buy the inverter pump off of amazon but after calling the local parts store they told me that i should also purchase the gasket set.

 

The last time I replaced an inverter cooling pump it only had hoses connected to it. I'd be curious as to where a gasket could be replaced.

Granted, I replace these pumps by removing the driver side headlight and using pinch style hose clamps to stop any drainage from the hoses. Maybe they're assuming you're going to drain all the coolant from the inverter loop and want you to replace the aluminum crush washer at the drain plug. If that's the case, then they're talking about a 50 cent aluminum crush washer. The Toyota Inverter cooling pumps I've purchased have always included this crush washer in the box.

 

P0A93 does not necessarily mean you have a failed inverter pump. If there's no power going to it (like if a rat chewed some wires), you would also get that code.

 

Always the rats get the blame. What if it was the chipmunks? They never seem to get the blame.

 

Recall from my vehice you and I deduced about 80000 miles life on those pumps, and then consider replacing.

 

I think 80k miles is a good guideline. Although some low mileage cars with 60k miles are now on their 3rd pump