Results 1 to 14 of 14

Thread: Toyota Prius software "fix" results in lower mileage

  1. #1

    Exclamation Toyota Prius software "fix" results in lower mileage

    Toyota Prius software fix may reduce fuel efficiency, experts say

    http://www.latimes.com/local/califor...218-story.html

    Ralph Vartabedian
    By Ralph Vartabedian
    Feb 18, 2018 | 7:00 AM
    Toyota Prius software fix may reduce fuel efficiency, experts say
    About 800,000 Toyota Priuses were recalled in 2014 to address overheating. Some drivers and experts who studied Toyota documents say the company's software fix resulted in a reduction in fuel economy. (Joe Raedle / Getty Images)

    When Robert Enger took his Toyota Prius into a dealership for a safety recall, he didn't expect that his fuel economy would drop.

    Just six months after buying the new 2013 Prius, Enger learned that the company was recalling it to fix the car's hybrid electrical system, which was overheating and frying itself. A technician plugged the car into a diagnostic tool that installed new computer code in two electronic modules. That was supposed to fix the problem.

    The repair itself has become controversial amid allegations that the electrical systems are still overheating after the software fix. But Enger noticed something else: His fuel economy dropped by 5 miles per gallon in city driving. Enger, an electrical engineer from Hermosa Beach, checks his mileage every fill-up, dividing the number of miles he drove since the last fill-up by the number of gallons he pumped to top off the tank.

    About 800,000 Toyota Priuses in the U.S. were recalled in 2014 to address overheating that damages the car's inverter, a key part of the electrical power system. A lawsuit brought last year by one of Southern California's largest Toyota dealers asserted that the software fix did not solve the overheating problem and could lead to an abrupt loss of power. A related complaint by the dealer is now under review by the National Highway Traffic Safety Administration.

    Academic experts contacted by The Times said it is likely the software change reduced the car's fuel efficiency. And a lawsuit this month in federal court makes allegation that Toyota "concealed from consumers that the software reflash decreased the fuel efficiency — defeating the very purpose of owning these hybrid vehicles."

    A statement by Toyota did not directly address questions about whether fuel economy and emissions are affected, but said the company would defend itself against such allegations.

    The company's documents show it modified not only software that controls the inverter's function, but also the software in the vehicle's powertrain control computer that determines how much power is supplied to the transmission by the gasoline engine and by the electric motors, according to the experts, hybrid vehicle engineers at major academic research centers.

    The inverter, a device about the size of a large shoe box, boosts the battery's 200 volts to about 500 volts for the electric motors and converts the battery's direct current to alternating current (similar to what comes out of a household outlet). When the brakes are applied, the power flows in the other direction to charge the battery.

    The change in the powertrain software and evidence of physical problems in the inverter probably shows that the company's modification reduced the power supplied by the battery and increased reliance on the Prius' four-cylinder gasoline engine, according to the academic experts who have reviewed those filings. If so, the car's fuel economy probably dropped and its emissions increased, they say.

    The Prius has an EPA fuel economy rating of 51 miles per gallon in city driving for the 2010 model and 49 mpg for the 2014 model. Enger said his city driving mileage dropped from 49 mpg before the software change to 44 mpg afterward.

    Assertions that the Toyota software change decreased the car's fuel economy are contained in a lawsuit seeking class-action status filed this month in U.S. District Court in Los Angeles. "Unbeknownst to drivers, Toyota reduced the vehicles' fuel efficiency, which is the main reason why consumers purchase Priuses," it alleges. The suit by two Toyota owners, filed by Los Angeles attorney Skip Miller, contends that Toyota's inaccurate fuel efficiency claims violate various consumer protection laws and result in fraud, false advertising and breach of contract.

    Roger Hogan, who owns two big Toyota dealerships in Southern California, has sued Toyota, alleging that more than 100 Priuses have come to his service departments with failed inverters after the software fix was made.

    Hogan's suit said that Toyota was slow to notify owners of the defect. It said that the company waited several years to issue the recall for the basic Prius after knowing about the problem and then waited another 18 months to extend the recall to the Prius V.
    Toyota of Claremont refuses to sell these Priuses because, a lawsuit alleges, they have a defect that can cause the cars to lose power. Owner Roger Hogan, center, filed the suit.
    Toyota of Claremont refuses to sell these Priuses because, a lawsuit alleges, they have a defect that can cause the cars to lose power. Owner Roger Hogan, center, filed the suit. (Gina Ferazzi / Los Angeles Times)

    Toyota officials at the company's U.S. headquarters in Texas issued a statement disputing the allegations in the class-action suit, saying they are without merit. They previously said the Hogan suit is without merit.

    "Toyota's focus remains on the safety and security of our customers, and we stand behind the effectiveness and appropriateness of the Prius inverter recall remedy," the statement said. "Due to the pending litigation, we cannot address the specific fuel economy claims in detail at this time, however, we intend to defend against them vigorously."

    The company notified the California Air Resources Board of the software change in January 2014, saying that that it made "no significant difference on emissions and fuel economy," according to a board spokeswoman. NHTSA referred questions about the performance to the Environmental Protection Agency, which did not respond by the time of publication.

    The Times interviewed more than a dozen Prius owners who described reliability and fuel consumption issues with their Priuses. When the inverter overheats, the car can suffer a total loss of power or enter what Toyota calls a "limp home mode." When it happens, the dashboard lights up with warnings.

    Kathleen Ryan, a Marina del Rey Prius owner who got the software fix in 2014, was driving in the fast lane on the 91 Freeway in January, cruising along at 70 mph, when suddenly "it felt like somebody pulled the emergency brake."

    The car slowed down to 15 mph and Ryan had to cross three lanes of high-speed traffic that was swerving around her slow car. Several California Highway Patrol Officers on the shoulder, who had stopped to deal with a stalled big rig, told her she was lucky to be alive, she said.

    "If I had been in an accident, nobody would know how it happened," said Ryan. "They would say, 'Oh, this old lady doesn't know how to drive.' If somebody dies, we wouldn't even know how it happened."

    Jason Levine, executive director of the Center for Auto Safety, said that a car in limp-home mode may be better than a full stall, but still puts drivers in a "freaky" situation. "You have gone to a large golf cart," he said.

    Levine and others compare Toyota's software fixes to Apple's secret modification of software that controls the iPhone, slowing down the device as the battery ages and loses its ability to hold a full charge. The Securities and Exchange Commission and the Justice Department said in January they were launching investigations into Apple's practices.

    In many cases, the inverters fail when drivers step hard on the accelerator or brake hard, which subjects the inverter to high loads. In its recall notice to owners, Toyota suggested drivers should temporarily take it easy on their Priuses: "Until the remedy is performed, drivers should avoid placing a high load on the hybrid system by avoiding full throttle application when possible."

    The company has been struggling with the overheating problem in the Prius as far back as May 2011, according to a "defect information report" that it filed with federal safety regulators in 2014. Its engineers examined the possibility that solder joints were cracking, a result of "excessive thermal stress."

    In following years, engineers found cracks in the solder, but could not find a problem in its manufacturing process. Later, the report said, the cracks were not turning up in the wagon version of the vehicle, the Prius V, which has the same inverter. By 2014, Toyota finally settled on changing the software in the inverter and engine controller. It told federal regulators it would sent owners notices by 2015.

    The overheating occurs in special electronic devices, known as "insulated gate bipolar transistors," or IGBTs, which boost voltage and convert the DC power from the battery to AC power.

    Heath Hofmann, an electrical engineering professor at the University of Michigan and an expert in hybrid vehicle power systems, describes the transistors as high-power switches that turn on and off thousands of times per second. The auto industry is trying to find a substitute for the silicon transistors, but so far continues to use IGBTs. It is likely the transistor loads are at the heart of Toyota's problem, he said, based on the defect information reports.

    "It strongly suggests that they did something to change the vehicle's overall power management system," Hofmann said after looking at some of the Toyota recall documents. "The likely thing they did was reduce the power running through the inverter and the motor generator, particularly if they are having problems in high power demand situations."

    Michael Pecht, a University of Maryland professor who founded the school's Center for Advanced Life Cycle Engineering, which focuses on electronics reliability, also reviewed the Toyota recall documents. "Clearly, they are saying the problem is in the IGBT, but they couldn't find the cause for two years," he said.

    Pecht said the software fix to reduce temperatures in the inverters may help, but "it is just going to delay when the failure occurs. My gut is that the software fix saves money. This is really serious. The inverters need to be replaced."

    In his lawsuit, Hogan alleges that replacing an inverter costs more than $2,000, while the software fix costs the manufacturer $80.

    Hogan said a few Toyota owners have returned to his dealership, saying their Prius suffered a loss of fuel economy after the software fix. A few Prius owners contacted by The Times said they did not notice any change in their fuel economy. Other Prius owners have made the same complaint as Enger in Toyota chat rooms, saying it "detunes" their cars and increases the use of the gasoline engine.

    In many cases, however, Prius owners may not know their fuel economy has degraded because they don't routinely check it or they may not associate it with the software recall.

    Enger, the Hermosa Beach engineer, said he tried to get answers from his dealer and then finally called Toyota's customer service hotline. He said he wasn't able to get to the bottom of his problem with customer relations.

    "It was like talking to a cat," he said.
    Another mark of a tyrant is that he likes foreigners better than citizens, and lives with them and invites them to his table; for the one are enemies, but the Others enter into no rivalry with him. - Aristotle's Politics Book 5 Part 11



  2. Remove this section of ads by registering.
  3. #2
    A lawsuit brought last year by one of Southern California's largest Toyota dealers asserted that the software fix did not solve the overheating problem and could lead to an abrupt loss of power. A related complaint by the dealer is now under review by the National Highway Traffic Safety Administration.

    Interesting. At first glance this looks serious. One would be tempted to think "Oh man, if one of their largest dealers had to bring a lawsuit, it must be serious!"

    But it's just weasel words. I talk to customers like this all the time - "Our largest customer in Cincinnati" is a 30-employee shop that sometimes can't find its ass with both hands.
    Large customers don't bring lawsuits - little, annoying, meaningless, low-revenue customers do. How many Toyota dealerships are there in SoCal? Google maps shows 20 (more than I thought) but really how many cars do you need to sell to be "one of the largest"? Meaning, how many to get into spot #9 - and one of those is a used dealer to boot.

    Point is, you can always - always - find a company willing to bite the hand that feeds it.

    This sounds exactly like the accelerator problem from a few years ago - made out to be a bigger problem than it is.
    Don't get me wrong, I think Toyotas are $#@! and would love nothing more than for their market share to be taken over by companies like Mazda that seem to like making cars instead of (as AF put it some time ago) "shapeless grey people pods". I just don't think this is what's going to sink them.
    There are no crimes against people.
    There are only crimes against the state.
    And the state will never, ever choose to hold accountable its agents, because a thing can not commit a crime against itself.

  4. #3
    Academic experts contacted by The Times said it is likely the software change reduced the car's fuel efficiency. And a lawsuit this month in federal court makes allegation that Toyota "concealed from consumers that the software reflash decreased the fuel efficiency — defeating the very purpose of owning these hybrid vehicles."
    Ummmm,

    The 'very purpose' of these vehicles is to mollify liberal legislators and make treehuggers think they're helping the environment...

    Hybred cars use more of the earths resources during their lives than old pick-up trucks do when everything involved is factored in.

  5. #4
    Enger, an electrical engineer from Hermosa Beach, checks his mileage every fill-up, dividing the number of miles he drove since the last fill-up by the number of gallons he pumped to top off the tank.
    Thanks for explaining the process to us Mr. Vartabedian. I'm sure your readers couldn't have figured out how to do that on their own.

  6. #5
    Quote Originally Posted by specsaregood View Post
    Thanks for explaining the process to us Mr. Vartabedian. I'm sure your readers couldn't have figured out how to do that on their own.
    You'd be surprised I think.

    I'm no math genius, and yet I often get the thousand yard stare when I try to explain to somebody how to do time, speed and distance calculations or why you should time everything in 6 minute blocks.

  7. #6
    Quote Originally Posted by tod evans View Post
    Ummmm,

    The 'very purpose' of these vehicles is to mollify liberal legislators and make treehuggers think they're helping the environment...
    No, many people buy Prius cars because they are excellent, well built, and cost effective vehicles.

    I own one and it has needed no serious maintenance in the 4 years I have owned it and I average about 45mpg making gas nearly free. Not to mention that using it to drive for Uber means the car paid for itself in the first 6 months of owning it.

    So for over 3 years I have a car that actually makes me money. To most people their cars are a liability, not an asset. The Prius is an amazing and impressive design and I highly recommend them.

    At first I felt like a pansy driving it around, but then I realized that when I put it in full power mode and I don't have any passengers, I can beat almost any non-performance car from a dead stop.
    __________________________________________________ ________________
    "A politician will do almost anything to keep their job, even become a patriot" - Hearst

  8. #7
    Quote Originally Posted by Matt Collins View Post
    No, many people buy Prius cars because they are excellent, well built, and cost effective vehicles.

    I own one and it has needed no serious maintenance in the 4 years I have owned it and I average about 45mpg making gas nearly free. Not to mention that using it to drive for Uber means the car paid for itself in the first 6 months of owning it.

    So for over 3 years I have a car that actually makes me money. To most people their cars are a liability, not an asset. The Prius is an amazing and impressive design and I highly recommend them.

    At first I felt like a pansy driving it around, but then I realized that when I put it in full power mode and I don't have any passengers, I can beat almost any non-performance car from a dead stop.
    I got better mileage out of my 2013 diesel Jetta, and if wasn't for Uncle Sucker's fatwas on diesel fuel and engines, I could have gotten almost twice that, had I the ability to buy a European diesel Jetta and had access to real diesel fuel.

    I also beat you from 0-60 by two seconds.

    https://www.zeroto60times.com/vehicl...-60-mph-times/

    The TDI Jetta was an upgraded package, that cost the same MSRP as a base model Prius.

    In addition, it was fun to drive, especially with the six speed manual, low profile tires and a little upgrade to the sway bars I had installed.

    But I can't have my car, because Uncle.

    And I don't want a glorified golf cart.

    That said, I won't question Toyota's build quality and low maintenance.

    Only goes to show what can be built in the US if given the chance, the two most reliable Toyota vehicles, the Camry and Corolla are built here.
    Last edited by Anti Federalist; 02-19-2018 at 12:29 PM.

  9. #8
    Not to mention that using it to drive for Uber means the car paid for itself in the first 6 months of owning it.
    Heh, piloting and Ubering.

    Both your sources of income will outsourced to the robot overlords before long.



  10. Remove this section of ads by registering.
  11. #9
    Quote Originally Posted by Anti Federalist View Post
    I got better mileage out of my 2013 diesel Jetta, and if wasn't for Uncle Sucker's fatwas on diesel fuel and engines, I could have gotten almost twice that, had I the ability to buy a European diesel Jetta and had access to real diesel fuel.

    I also beat you from 0-60 by two seconds.

    https://www.zeroto60times.com/vehicl...-60-mph-times/

    The TDI Jetta was an upgraded package, that cost the same MSRP as a base model Prius.

    In addition, it was fun to drive, especially with the six speed manual, low profile tires and a little upgrade to the sway bars I had installed.

    But I can't have my car, because Uncle.

    And I don't want a glorified golf cart.

    That said, I won't question Toyota's build quality and low maintenance.

    Only goes to show what can be built in the US if given the chance, the two most reliable Toyota vehicles, the Camry and Corolla are built here.

    Hell, Honda CRXs in the 1990s got around 45 mpg. technology from over 30 years ago.

  12. #10
    Quote Originally Posted by specsaregood View Post
    Hell, Honda CRXs in the 1990s got around 45 mpg. technology from over 30 years ago.
    Ford Falcons in the 1960s without a single transistor got 20-30.

    https://fordsix.com/viewtopic.php?t=49519

  13. #11
    Quote Originally Posted by Anti Federalist View Post
    I got better mileage out of my 2013 diesel Jetta, and if wasn't for Uncle Sucker's fatwas on diesel fuel and engines, I could have gotten almost twice that, had I the ability to buy a European diesel Jetta and had access to real diesel fuel.
    Yes very true. The US government has screwed the US diesel market... well that and GM in the 80's giving it a bad reputation.



    Quote Originally Posted by Anti Federalist View Post
    Heh, piloting and Ubering.

    Both your sources of income will outsourced to the robot overlords before long.
    Ubering, yes, I agree, it won't be around in 5 years. There is already an autonomous fleet of Uber cars in Pittsburgh (although they still have a safety operator just in case).


    But as previously mentioned elsewhere, flying will be decades before automation takes a human job in the airlines or heavy cargo.
    __________________________________________________ ________________
    "A politician will do almost anything to keep their job, even become a patriot" - Hearst

  14. #12
    Quote Originally Posted by Anti Federalist View Post
    You'd be surprised I think.

    I'm no math genius, and yet I often get the thousand yard stare when I try to explain to somebody how to do time, speed and distance calculations or why you should time everything in 6 minute blocks.
    Why time everything in 6 minute blocks?
    “The nationalist not only does not disapprove of atrocities committed by his own side, but he has a remarkable capacity for not even hearing about them.” --George Orwell

    Quote Originally Posted by AuH20 View Post
    In terms of a full spectrum candidate, Rand is leaps and bounds above Trump. I'm not disputing that.
    Who else in public life has called for a pre-emptive strike on North Korea?--Donald Trump

  15. #13
    Quote Originally Posted by kcchiefs6465 View Post
    Why time everything in 6 minute blocks?
    Because there are ten of them in an hour.
    Quote Originally Posted by Swordsmyth View Post
    We believe our lying eyes...

  16. #14
    Quote Originally Posted by kcchiefs6465 View Post
    Why time everything in 6 minute blocks?
    You are tracking a radar target to determine risk of collision.

    It moved 1.2 nautical miles in six minutes.

    You know it's speed is 12 knots.



Similar Threads

  1. Replies: 1
    Last Post: 04-25-2015, 05:08 PM
  2. Replies: 5
    Last Post: 02-21-2015, 08:31 PM
  3. Watch DARPA Hackers Take Control Of A Toyota Prius
    By ClydeCoulter in forum U.S. Political News
    Replies: 12
    Last Post: 07-24-2013, 07:46 PM
  4. Replies: 15
    Last Post: 08-21-2012, 12:51 PM
  5. Google News: "Rand Paul" = 7283 results, "Sarah Palin" = 6025 results
    By TheFlashlight.org in forum Rand Paul Forum
    Replies: 0
    Last Post: 05-23-2010, 11:08 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •