NHTSA Recall No. 20V-369

This is a newer one on the same old theme. Defect Information Report

About 205,000 Prii (2013-15) and 62,000 v wagons (2014-17) that were left out of the earlier recall because they were known to already have improved thermal management algorithms from the factory, suggesting they wouldn't be affected.

Seems people drive differently enough in Japan and North America that the issues were only showing up here, and took some effort to pin down.

Apparently, just being the kind of maniac who floors the go pedal from a stop is not enough to overheat the transistors in these cars. The temperature stays within limits if you do that.

The problem appears if you're the kind of maniac who stomps to about 2/3 go pedal right from a stop, and then gradually pushes further to the floor. Whatever the firmware is doing to manage temperature seems to have some sort of blind spot for that case.

PriusChat has a lot of armchair experts who know that the only possible way to improve the transistor thermal management in the firmware is to cap your acceleration or clobber your fuel economy, and considering the amount of HV control firmware they have written themselves, of course that has to be true, as has been confirmed by some of the world's best precisely-calibrated butt-dynos and by the occasional painstaking comparison, worked out to decimal places, of a week of MPGs post-recall to five years of MPGs from before, all under precisely re-created driving and weather conditions.

One recent poster did report (in one of the cars covered by the earlier recall) that a couple of CAN-bus-observable control parameters were different after the recall, compared to recollection of what they were before. I have not seen any other similar report but that one.

In another recent thread that talked about how useful it would be for some people about to have the work done to collect and post a good set of 'before' data before going for the appointment, and the same set of 'after' data later, so the knowledge in the PriusChat community about driving effects of the recall, if any, could start to move beyond handwaving ... if I remember right, there was one person who was about to have the work done, mentioned being willing to do that for the good of the cause, and then didn't.

So far, that's still pretty much the state of what we know about the driving effects of these updates.

 

I have had it done on my 2015. Reduced MPG by 3 gallons. Car engine tends to run more often than before. It sucks. But the alternative could be worse.

 

some have said they experienced lower mpg's after having the update, but i think most have not noticed any change.
there's a uge thread here somewhere on the subject.

i haven't done mine, because i also drive like a granny. 2/3 of the accellerator and then slowly flooring it only happens in california.

 

Haven't done mine either, I did mark "completed" on the recall section of my car fax but I never plan to sell my Prius according to my blackstone oil analysis result. I still do lower full grill block so the inverter will heat up quicker & stay hot during the summers also

 

Got my recall notice in the mail today so I’ll call Monday to schedule it. Stop gap by Toyota to minimize the class action lawsuits. It’s a shame (crime) that Toyota is not being made to properly repair the problem by NHTSA. More people will die when the inverter overheats and causes the car to shut down at high speed in traffic. Sure hope that it’s not my wife or I...or any of you. I’m considering selling my 15 and getting a lease return 17 with the safety upgrades. I was originally planning to keep the 15 a minimum of 10 years.

 

There were additional safety features added mid year in 2017. I have an early one

 

The 15 is my wife’s car. I drive a later model 17 with the safety enhancements and love it. 17’s are coming off lease now which makes them a pretty good deal financially with mileage in the low 30’s.

 

I got the same recall notice. Had the software update on the Prius last week and so far, i didn't notice anything different.

I completely rely on the on-board MPG reading so will know when I refuel next time regarding the mileage but am told the update is very similar to the update your get on your phone!

That said, does anyone know how to verify if software update was done? Is there a version number that shows up in the display?

 

As far as I know, the version number (“Calibration ID,” in Toyota’s terms) isn’t shown on any of the car’s built-in displays. You’d need to use a Toyota Techstream diagnostic system, or equivalent, to view this information, as described on pages 14–17 of the technical instructions (PDF) for the recall.

 

Seems to have happened to me. I‘m getting 39 MPG on my 2014 Prius post-update! Bringing it to the dealership in a few days. Here’s hoping they do the right thing and fix it for free.

 

If the car already has the latest software, I don’t know what a dealer could do about a perceived reduction in fuel economy, unless there is some obvious and unrelated problem, such as a dragging brake.

If you insist, they might connect a Toyota Techstream diagnostic system, use the Health Check feature to look for diagnostic trouble codes (DTCs), and if they’re thorough, verify the calibration IDs, as I described in post #11. Assuming they don’t find any DTCs—which is unlikely, if you haven’t seen any warning lights—and the car has the expected software, they’ll return the car to you, and perhaps charge a diagnostic fee.

To be clear, I don’t mean to claim that the software updates in the safety recalls have, or have not, had effects on fuel economy, only that addressing such matters is beyond dealers’ capabilities and expertise.

If you’re very lucky, the dealer would agree to open a case with Toyota’s Technical Assistance System, the dealer-only support line, but if the outcome is anything other than a polite suggestion to see the line in the sales brochure (PDF) that says, “Actual mileage will vary,” I’d be surprised indeed.

Please do let us know what happens, though.

 

For the people that had this update. How long do you have to leave your car at the dealer?

 

Dropped mine off at the dealer in the morning at 8. I was told it would be ready by 5. Then they called me during lunch and said "It is done."

 

A firmware update won't ordinarily take more than an hour, once your car gets to the head of the line.

You can help if there's not a lot of stuff in the hatch area when you go in, as they have to pull up the planks and attach 12 volt power support to the battery.