Latest Software Update Safety Recall Resulting in 8mpg less...

I took my car in for it's 35K service, and stated that I was still having the drop in millage, and that it had gotten worse for in-city driving, where EV mode kicks in a lot (e.g. engine still running after I side to a slow stop, and EV mode not being available at gliding speeds as low as 10 MPH, even though the engine is warm and battery full).

They were not sure about the EV Mode issue, but to my surprise... The service manager admitted that I lot of people were having drops in MPGs and complaining about it.

Apparently I am no longer the only one having the problem, or crazy. He told me that Toyota is aware of the issue but does not know what could be the problem or even if it is related to the safety recall. The instructions from Toyota to the dealers is run health check, and as long as it passes health check and gets over 38 MPG average... there is nothing they can do. They encouraged me to talk to Toyota, but I have been there and done that 3 times already with no success and negative experiences. They just bounce it back to the dealer. It is a vicious circle.

Around the city I am now less than 38MPG, but their test drive would be a mix of highway and city... so my average would be over 38MPG. There seems to be a known problem, but they don't seem to be doing much to collect information or experiment to figure it out. There are so many things they could do, and I had even spelled out and recommended to them before, but they don't.

On the positive side.. it is no longer true that...
- I am the only person the dealership and Toyota have heard has this problem (even though this thread shows others do and have reported it)
- I am making stuff up (even though I could show them millage records, and they do not take any notes on your records if you call or talk to them)
- I started driving like a maniac (which my wife gets the same mileage driving my car vs. both of us getting a lot better in her's driving the same as ever)
- My air filter is dirty (even though they replaced it)
- Change to summer fuels (summer blends didn't happen until a couple of months later and the winter blends came back it didn't make a difference)
- Major change in weather (I live in San Diego on the coast and didn't move or change locations and it has been almost a year)
- Running the AC more frequently (I live in San Diego at the coast and didn't move or change locations)
- Tires at the wrong pleasure (they checked them and they were fine)
- New tires (although the problem occurred before the new tires, and they are rated very high for millage on the Prius)
- Not filling my tank the same each time (I do, and it would even out over time)
- Using different gasoline and stations (I go to the same station and get the same type of gas)

 

It has always been my experience with a car dealer is there are some issues that they will not admit is an issue, therefore, they will do nothing about it.

 

Did you ever try to replicate these benchmark data?

• drive 15 minutes to warm-up car, transmission, and tires
• find a level highway that you can set the cruise control for 10 miles
  
  • ideally do a loop
  • alternatively, do two passes, opposite direction
• record MPG after reaching cruise control speed for at least 10 miles
  • if doing two passes, reset trip-meter after setting cruise control

We need one benchmark at or below 40 mph when the car is in 'hybrid' mode. Minimize the electrical loads including AC. Use the windows.

We need a second benchmark at or above 45 mph when the car is in highway mode. Same as above, avoid extra loads on the car, use the windows.

Speed is set and managed by using cruise control.

Bob Wilson

 

No I have not... I can clearly state that my wife's 2011 runs extremely different from my 2012. Until Toyota really wants some data (unless they don't need it because they already have the data), it will do no good, if/when they do want data, they will probably do it on their own terms and specifications. I was hoping others that were having this problem could confirm that their dealers are also aware of the problem and that they also know that Toyota knows.

 

Toyota of Fort Worth is aware and they wont do anything about it.

 

When asked to run benchmarks:

The reason for running two benchmarks and comparing to my 'off the lot', May 2009 data:

• below 40 mph - the car runs in 'hybrid mode' so the engine turns OFF when it can. If the patch had an effect in this area, we would see it as significantly lower MPG because the engine was running instead of OFF.
• above 45 mph - the car runs the engine all the time and the patch should have no effect. But if this particular car has a problem with rolling drag, aerodynamic drag, or engine efficiency, it will not have similar performance to my 'off the lot', unpatched car.

The benchmark uses cruise control and a fixed route, two opposite direction passes, to minimize human, wind, and elevation effects. It is a vehicle test without having to hire a tuning cell (i.e., dynamometer.) Since your wife's car works just fine, it would help to run the same benchmarks with her car. I reran my benchmarks and could find no difference after the patch. This does not rule out performance regions where the patch effects might be found, the only thing interesting about this thread.

Everyone has a right to choose how they deal with the problems in life. I prefer engineering, running benchmarks to find reproducible facts and data. Since we have nothing in common, I'll unsubscribe from this thread.

RECOMMENDATION: sell the problem car and replace it with a non-Prius or a later model Prius. Regardless, get rid of the problem car.

Good luck,
Bob Wilson

 

When problems are created by others (Toyota with their upgrade), I feel very disinclined to doing anything more than a quick assessment, report it, and leave them sort out the mess they created. I'd be decidedly averse to being drawn into a significant investment of time and resources, to diagnose what they've done. Larry's seeing an obvious variation in two (supposedly identical) cars under his roof. And he's not alone.

Unfortunately, it looks more and more like this is going to be Toyota's "Honda" moment.

 

well, here you go.

and I assume you didn't check the 12V battery or do the ECU reset either, right?

 

I specifically had them check the 12 volt battery and asked if it was bad or running low, that it would prevent EV mode from kicking in. I was told no. I had also already tried the hard reset by disconnecting the 12 volt battery and there was no change.

 

The one thing that I would really like them to try but they won't do (because they say it is not possible and they don't have instructions) is to reapply the update. It seems that if something did go wrong with the update, they could do it again. I do not know of any computers or devices that if they have reprogrammable flash memory can't be re-flashed. It seems like a very simple test for them to do.

 

I'm sure I read here, of someone having just that done, with positive results. I'm probably repeating myself, lol.

This seems a slumbering giant, with a small but seemingly definite number of the upgrades going sour. I hope it wakes up, not sure what it would take.

 

yeah, that part sucks. have you tried a different dealership?

 

A shrinking 'giant' because subsequent Prius are not patchable . . . they ain't making them like that anymore. Furthermore, the 'giant' pool of candidate vehicles shrinks from accidents, warranty expiration, and resale. As for the size of the 'giant', more than one have reported no effect from the patch. It is not a universal symptom.

About 3% of the fleet go to the salvage yard each year from accidents and equipment failures. As warranties expire, it is the owner's problem. When sold, the new owner may come here and we'll work with them to fault-isolate. But without a way to reliably reproduce the problem, it remains a rumor and not a demonstrable fault.

Bob Wilson

 

Frankly, I think this "problem" is more like an upgrade "glitch" you can get on a PC when something buggers during a patch. Unfortunately, there's no way to revert to the pre-upgrade status and try again, so it sucks for those to which it happens.

About all Toyota can do is take the parts affected by the upgrade and replace them with pre-patch components and see if performance goes back to "normal." Then, apply the patch and see if the problem repeats. If not, it's either something with the OEM components that didn't take well to the patch or a buggered install process that happens X% of the time. Unfortunately, I'm sure this is not an inexpensive solution for Toyota.

 

In the first year, we had a lot of folks report their mileage, pre-patch, that led to these charts:

To get mileage under 50 MPG, just drive faster than 70 mph. But also notice some are able to get substantially better MPG at speeds under 30 mph.

There is another approach:

Here we see two effects:

• cold-start overhead - short trips
• high-speed - +80 miles per day, requires higher speeds

It doesn't take 'blaming a patch' to get crappy mileage. Regardless, hopefully they will sell their Prius soon so the new owner can work with us to figure out what is going on.

Bob Wilson

 

i'll bite. why not?

 

^ I'd assume because they come from the factory with the revised programming.

 

Any that were in transit would have been fixed at the dealer before sale and/or the port of entry.

So if a newbie comes reporting a problem with low MPG:

1. Ask to have the standard questions answered.
2. If still nothing, next level debug
   • Ask for benchmark runs to see if it is car 'hybrid' and/or 'highway' mode.
   • Share known risks: cold-start; high-speed; and hill climb
   • Investigate route and instrumentation

This presumes the owner/driver is curious. We then have a chance to learn something ... the reason why I'm here.

Bob Wilson

 

Bob,

I assume that this is directed to me. I have asked lots of questions, showed them my findings, and rebuffed all of their claims why I suddenly got worse millage. I have offered to let them borrow my car, and have asked them what they would need to proceed to figure out and fix the problem. I have spent lots of time with the dealer and Toyota Corp, only to find that they keep passing me back and forth between them. They did not want any evidence or data from me and will not give me any updates on the problem or what they are doing about it because it is proprietary. They have and will continue to reject any data I give them, unless at some point they actually want some data. Until then, they absolutely do not want anything from me, or my help in trying to figure it out. I have continued to do some testing (comparing my 2012 with my wife's 2011) and she gets 20% better MPG than me on the same routes. I also mentioned this to the dealer and they said it is normal variance between cars. 20% difference on the same basic car is pretty amazing... but it show how little they care about data that shows there is a problem.

 

Hi Larry,

An engineer by choice, I am only interested in technology. I have been married too long to believe I can change minds. But technical things interest me.

So I don't think we share curiosity about machines and I have long ago given up on the people problem. But when folks reported a brake problem, I worked with others until we figured out what was going on ... a week later, Toyota came out with a fix and I verified it worked.

So GOOD LUCK!
Bob Wilson