Inverter Pump Failure, Code P0A93... Have I Fried It?

While driving home last night (New Years Eve…and from purchasing another Prius!) the Red Triangle, CEL and the Hybrid Warning lamp, (on the MFD) all lit up. The cruise control also shut down. Since we are “new†to the 2006 Prius (purchased last month)… we stopped and checked the manual to identify what the symbols meant. We were approximately 90 miles from home, drizzling rain and it was about 60 degrees.

After calling our road service provider…we finally came to the realization that it was going to be about 3 hours before help would arrive, plus towing to the nearest dealer was certainly not practical…considering the holiday and that it was almost 10:00pm. I decided to just drive it and see how it felt. Everything seemed to work ok.

About 5 miles from our house it felt like the engine sped up (almost like you pushed in on a clutch a little bit)… I let off the gas. It did not do this anymore. It is also a possibility it was just me mashing the pedal and not realizing it. My leg was cramping from not using the cruise control.

This morning I hooked up the Scanguage and found a P0A93 code (Inverter pump). I checked and the pump is definitely not pumping. Since we are “new†Prius owners…I didn’t find out about the recall that is applicable to our 2006 model until last week. I was going to take it in this week. I guess it’s obvious I should have done that last week!

The local dealer I will be using is about a 10 mile drive. Should I drive it to the local dealer (considering I drove it 90 miles last night), have it towed…or just shoot it and hope for the best! Any thoughts on what I may have damaged?


Also…The second Prius we purchased, yesterday, is an 08 Touring and is the same color, Silver Pine Mica, as the 06 Base we purchased last month. That should confuse our neighbors!

I'd have it towed. I drove mine 15 miles after the pump died, in cool weather across flat ground at no more than 40 MPH, but why take the risk?

Assuming that your car will start on Monday morning, I think it is reasonable for you to drive the car 10 miles to the dealer since the ambient air temp is relatively cold now.

congrats on both your purchases!:welcome:

To drive or not to drive...that "was" the question! It was a cool 48 degrees this morning so I drove the Prius to a hotel that is about 1/4 mile from the dealer. Tomorrow I will inform the dealer that that is where I stopped after the warning light came on (there is a measure of truth to that...) and get their recommendation to tow or drive the last 1/4 mile.

But again...I hope the 90 mile drive didn't fry anything in the hybrid system. I was, however, relieved to hear about several folks that drove for extended miles (further than I did) in the summer, and with mountains... and apparantly didn't suffer any ill effects.

I will update once the service is completed and I can evaluate the performance of the vehicle.

Thanks for the replies...and I'm glad I am part of the Prius family.

FlyboyTR

When the IC pump stops, the controls limit the amount of current allowed to flow through the inverter. Rather than allowing for full boost, you may only get 1/2 or 1/4 of the normal amount of current flow (which cuts the Ohmic heating by 3/4 - 15/16). This means that you are unlikely to fry anything, but the engine will have to work harder and occasionally rev higher. This also means that unnecessary systems are shut down, like A/C and charging the 12V battery. I'm surprised that you made it 90 miles without the 12V going dead! Maybe the prior owner installed an Optima yellow top. By the way, if it doesn't start this morning, check the 12V battery.

Best news of all is that your dealer will fix this for free! Just be extremely skeptical if they try to sell you on some other service, like an engine water pump replacement.

If you fried something, the car would not run, period.

Thanks for the detailed info! Sincerely appreciated. Actually I installed an Optima battery in it about 3 weeks after we purchased the car in November...so I guess that was a good thing. I'm currently waiting for the dealer to call me back with an update. I'll post it. Thanks again!

The dealer called me and he said they were doing the recall warranty work (inverter coolant pump and accelerator pedal). He went on to explain that the lights that were on on the dash were because of a “fuel run low situation.” I told him according to the owners manual the lights that were on (red triangle, yellow circle with ! and the red car with the ! in the middle on the MFD) indicated a problem in the hybrid system. He then said that according to the code the technician pulled, it was the fuel run low situation, not a hybrid problem. ...strange...since it had 1/2 tank of fuel and hasn't been below 1/4 tank since we purchased it. Again, the code I pulled with my ScanGuage indicated it was hybrid related.

Sort of makes me wonder about either the techs or the service writer… He also said the drive belt was starting to show signs of wear and quoted $125 to replace it. OK….well…this really doesn’t build my confidence in that dealer. I will just hope for the best and will report back here in a month or so with an update on how everything is continuing to operate. Any additional insight or things to keep an eye on will be appreciated! Thanks again...

OH...I guess it's time to read up on the belt change procedure. Should be simple!

Upon arrival at the dealer to pick up the car, I got the same story that I was given on the phone. The work order read: Customer states that engine light coming on as well as hybrid warning. Performed inspection on system had a code 3191 for fuel runout cleared and retested all OK.†The diagnostic charge was $45!

Since I had checked the codes prior to taking it to the dealer I know there was no fuel runout, 3193 code. There was however the P0A93 code. So…what happened to that code. I didn’t clear it. Is the fuel runout code a ploy to charge me the diagnostic fee? Sorry…but I’m having a really hard time buying this. They also completed the obligatory once over for items that may need attention now or in the future. Again…I’m having a difficult time with this! All my tire pressures (checked/adjusted to) were at a perfect 32/32, including the spare. However, less than a week ago they were all at 42 and the spare at 60. My air filter is dirty and needs replacing…although, it’s new and only has about 800 miles on it. They topped off my windshield washer and engine coolant tanks…however, the levels were the same as when I checked them two days ago…and yes my coolant tank is still a little low! Later this week I plan to schedule a meeting with the Service Manager and ask for his explanation regarding my findings and concerns.

Don’t get me wrong…I’m glad the inverter coolant pump was replaced and the accelerator pedal modification, etc completed. But I still feel a little used. I pray that I did no long-term damage to the inverter and will count this as a learning experience.

Regardless of my frustration, I did purchase 8 quarts of tranny fluid ($8), 4 washers and a drive belt. The tranny fluid drain and fill only took about 30 minutes. Simple.

My thanks to this wonderful forum and the endless wealth of information. :cheer2:

From what you described the dealer does seem incompetent and/or deceptive. I would look for other dealers or local shops for future service/repair. Thanks for sharing your experience and good luck!

Yep, I believe you're right! Sad part is...I used the dealer that was recommended by local friends that drive Prius'. At least I have a couple more choices! Thanks!

I had the recall work done on my '04 over the holidays...about 74K miles on it. I was told I needed the serpentine belt replaced, a marker bulb was dead, and I needed a brake flush. The price for the belt came to about $128 which is close to yours. I'm not particularly mechanically inclined, so I had them do it. I looked at it after they replaced it and the top side was shiny and the underside was rust-colored and lots of cracks. I guess it needed it.

I declined the brake flush because from reading here I don't think it needs one 'til after ~100K or more.

I would say that $125 is a rather high for the belt replacement...but not totally out of line. However, that job should take about 10 minutes or less for mechanic that is used to working on the Prius. I'll be changing mine on Thursday. I changing the tranny fluid in the second Prius as we speak...it's currently draining.

Be aware, brake fluid absorbs water vapour. The dissolved water migrates to the lowest point of the brake system, usually the brake calipers, where it will lower the boiling point of the fluid AND will enhance the corrosion of the brake components. While the Prius may rarely need high boiling temp. brake fluid, it DOES need help avoiding corrosion in the brake system (like just about all other vehicles).

The recommendation in the auto industry is brake fluid be changed regularly. The time between changes will depend on average ambient humidity mostly. I've seen from 2 to 5 year intervals recommended. Be aware, while it's a good idea, it's also used by dealerships to enhance profits. Unfortunate, but true. Use common sense but do have the fluid changed from time to time.

FYI, MSRP on the belt is $17.72 -- about the cheapest OEM belt on the planet! Labor guide time is 0.5 hrs. Most dealers have a 1 hour minimum, so, yeah, $100 for labor, $17.72 for the belt, shop supplies and tax makes $120-something. Just another job that saves the average person $100 for DIY.

I suppose that the belt is another unnecessary yet plausible wear item to be pushed by service advisers during a warranty visit.

I hadn't really thought about a minimum shop time... very possible! Thanks.

About brake fluids... Living on the Gulf Coast where even on most dry days we're still looking at 80-100% humidity...not to mention our annual rainfall...brake fluid changes are important to me. I have a kit that attaches to "most" master cylinder tanks and the fluid is pressurized, with a fresh fluid feed. Basically just crack open the bleeder valves and let about an ounce or two out of each wheel cylinder and the job is done. On our other cars it takes me about 15 minutes, plus setup and clean up. I need to learn a little more about the Prius brake system first...but I'm sure the same process should work.

While I am all for DIY, this is one of those jobs which is difficult, if not impossible, without a factory-level scan tool. The bleeding procedure is several pages long in the service manual, and involves pulling and installing relays as prompted by the scan tool.

Thanks. I did take a quick look at the Prius braking system schematic...wow! Yep...it is a lot more invovled that any standard brake system!

Hi David:

Have you seen Hobbit's monograph on this topic ? He tentatively concludes that Prius brake fluid ages much slower than most cars because its use is buffered by regen braking. Apparently we can buy a test strip that qualitatively shows copper leaching, and use that test to decide when to flush the fluid.

I'm no expert, but I'm happy with this approach. If my front brakes ever need new pads, I'll check brake fluid copper content then.