By on February 4, 2010

Ford says emphatically no, but the evidence (such as it is) indicates certain similarities. Let’s take a look…

Toyota’s updated press release on the Prius brake issue reads:

Some customers have complained of inconsistent brake feel during slow and steady application of brakes on rough or slick road surfaces when the anti-lock brake system (ABS) is activated in an effort to maintain tire traction.  The system, in normal operation, engages and disengages rapidly (many times per second) as the control system senses and reacts to tire slippage.  A running production change was introduced last month, improving the ABS system’s response time, as well as the system’s overall sensitivity to tire slippage.

From Toyota’s press conference:

When driving on an icy road, the shift from the electronic brake to the hydraulic brake sometimes takes longer than usual

Consumer Reports’ paraphrase of the Ford technical service bulletin (TSB-09-22-11) reads:

electronic interference might cause the electronic brake-by-wire module to switch itself off temporarily. If that happened, the braking system would revert to a backup conventional hydraulic mode that preserved braking capability, but the pedal will drop over an inch. When the engine is restarted, the electronic braking system would resume…. Ford engineering representatives explained that the software threshold for establishing a fault in the regenerative brake system was set too sensitively, causing the system to transition to conventional brakes when it was not necessary.

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28 Comments on “Are The Prius And Fusion Hybrid Brake Issues Related?...”

  • avatar

    This barrage of techno-baddies makes the Curbside Classic series that much sweeter.

  • avatar

    On the surface, I’d say “apples and oranges”

    Toyota’s problem is NO braking while the vehicle decides which system to use. (arguably, its only a second… I’ve driven cars with worse brakes, and wrecked cars with brakes even worse then the aforementioned worse brakes…)

    Ford is locking out the regenerative braking due to a fault and falling back onto the hydraulic brakes. (According to the release…) There is no interruption in the braking. I don’t know if I would like the feel of loosing an inch of pedal travel, however… /shrug

    • 0 avatar

      The wording is different but it sounds to me like the same problem; especially if you watch the CR video.

      Ford states “there is no interruption” in braking, and this is true, only if hit the brakes all the way down. However, there is obviously a interruption in braking relative to how you would normally drive, which is similar to the user report the Prius user experience that Detroit Bureau originally reported. If you slam on the brakes for the Prius under similar situations, you would also engage emergency braking. However, the CR report isn’t clear of the road surface (if he hit a pot hole, etc)- which is how the Prius situation is being reported.

      The main story is how well Ford handled this. They obviously got a call from CR before they went to publication, realized that using the word ‘recall’ is unwise because they would be lumped together with Toyota. Offered a fix asap, and called it a “customer satisfaction program”. Barely any interest from the media even though it could have been relavent.

      Toyota could learn a lot from Ford’s handling, but at this point, anything Toyota says or does would be looked at cynically. They wouldn’t get away with calling it a “customer satisfaction program”; they could have a month or two ago. The fact is, Toyota is too damn slow and undeceive. They are confronted, they are thinking about it, and then they respond much later. Making the news on both occasions and dragging all of it out.

      For instance, Toyota is likely going to announce recall on Fri or Mon, get tons of negative news coverage again about a recall when they could have acknowledged the problem and announced a fix the same time.

  • avatar

    If by “related” you mean both vehicles happen to be hybrids and possess brake pedals then yes, I say you have uncovered a major scoop in the automotive news field.

  • avatar

    I still vote Toyota’s is 3-phase AC induction motor control problems (see my post in the other Prius thread).

    Ford may be seeing the same effect in their sensor data, but its triggering the failsafe condition (conventional brakes) rather than just allowing the situation spin out of control.

    Ie., Ford didn’t think the whole thing through, but they thought it through further than ‘Yota.

  • avatar

    The difference is that in the Toyota it is an actual safety issue – you may temporarily lose braking entirely, or the software that controls the brakes based on pedal input may not account for the traction and speed correctly and not apply enough force, even while you are getting the feedback you expect from the brake pedal.

    The Ford setup is not a failure of the system, it’s the failsafe engaging sooner than it has to. When the failsafe engages the pedal travels farther, but you never lose any braking or control of the brakes. Since Ford’s system isn’t even actually broken, after all, a failsafe makes sense to have, and the threshold is just set lower than some people apparently expect, Ford didn’t even have to issue a recall, but is doing so despite the bad press and comparisons to Toyota’s actual safety-hazard problems that are likely to result.

  • avatar

    The two problems are totally different.

    Toyota Prius: If, while braking, the car hits a bump/pothole/ice/gravel, the ABS kicks in aggressively, pulsing the brakes, reducing braking force and causing the car to speed up. Momentarily letting up a bit on the brake pedal and then pressing it again eliminates the ABS pulsing and restores steady braking effect. If the driver does nothing (does not momentarily lift up on the pedal), then the pulsing will occur for a couple of seconds, after which the ABS cuts out and steady braking resumes. This is based on my experience with an 02 Camry and 04 Prius that both had this annoyance. (07 Camry doesn’t have this issue in my experience.)

    Ford Hybrid: In some cases while braking, the regenerative braking system fails, causing the car to speed up and resulting in warning chimes and lamps flashing frantically on the dashboard. The brake pedal then drops an inch, at which point the driver can solve the problem by pushing further on the pedal to utilize the hydraulic braking system to slow the car. If the driver does nothing, the car does not slow down. Cycling the ignition switch resets the system.

    Summary: The Ford has a defect that causes one braking system’s failure and requires driver intervention to overcome (press pedal further to invoke backup system). The Toyota has an overly aggressive ABS that interprets the split second wheel rotation speed variance (between wheels) as a slip condition, and engages for a couple of seconds reducing braking power momentarily and then corrects itself. This is no different from undesirable ABS engagement when driving on gravel, which applies to pretty much all cars with ABS.

    • 0 avatar
      tooling designer

      LOL, nice effort though!

    • 0 avatar

      Um, no. The Ford regen braking system does not fail, it switches between regen and hydraulic braking without needing to.

      Let’s be fair here, both Ford and Toyota are recalling the vehicles, just using different names for the same actions. Toyota’s getting unnecessarily (and unfairly) dragged through the mud here, but this doesn’t mean we need to start bashing the other makers too.

      Edit: Z71_Silvy, Consumer Reports checked with Ford on this, and simulated the event. Again, what happens is the pedal drops an extra inch when regen braking stops and you have to depress it further to keep braking power going. The brakes did not fail, and Consumer Reports says as much in the video they released. watch the video at 1:15 on. This is not the brakes failing, it’s a software glitch.

    • 0 avatar
      Greg Locock

      “In some cases while braking, the regenerative braking system fails, causing the car to speed up ”

      Oh do tell, how does a brake failure cause the car to speed up?

    • 0 avatar

      @g.locock: When going downhill? (I think Yotafan really meant something more like “rate of deceleration decreases.”)

    • 0 avatar

      Actually, it’s the “perception” of not slowing down when you apply the
      brakes. For however long you’ve been driving, when you hit the brakes
      the car slows down. When it doesn’t slow down, your brain sees it as

  • avatar

    They are similar…but only one results in a failure of the braking system…the Ford.

    To quote Consumer Reports:

    As one of our senior engineers slowed for a stop sign at the turnoff to our test facility in East Haddam, Connecticut, the brake pedal went unexpectedly further down than normal but the car barely slowed. He zoomed through the turn, with brake-system warning lights illuminated on the dash. The car more or less coasted to a stop, with what our engineer described as minimal brake feel.

    After switching off the engine and then restarting it, everything returned to normal – no warning lights and full braking capability.

    And I heard Ford fixed the issue on the line back in October……why so long for a TSB? Hoping no one would notice? That would be par for the course…

    Toyota realized there was a problem last month and already issued a TSB…

    • 0 avatar


      The factory representatives confirmed that our car’s brakes had experienced a fail-safe mode incident, but they didn’t see a brake failure. They brought our car back to the Consumer Reports’ Auto Test Center with its electronic brake module disabled so we could see for ourselves. Our test director and senior test engineer tried it out. The pedal travel was long and the pedal felt mushy underfoot, but when the pedal was pushed firmly down, the brakes did stop the car effectively.

      There is no failure in the Ford braking system, the safety protocol failsafe just kicks in sooner than some people are comfortable with (which given the alternative, isn’t a necessarily a bad thing). Also, as stated in the video:

      “You do get full braking, and power brakes come in so you can actually stop the car.”

      The video also states it as ‘perceived’ brake failure, not actual brake failure. All you have to do is push down the pedal a bit further.

  • avatar

    Somehow, some way this all GM’s fault.

  • avatar

    What part of Ford’s hybrid technology is licensed from Toyota?

    IIRC, Ford tried to keep quiet that they were licensing Toyota Hybrid technology for the hybrid Escape; publicly, Ford said they were capable of engineering their own hybrid systems … but this was believed by some to be a smokescreen for technologies built upon that which was licensed by TMC.

    Can anybody shed light on if Ford licenses something of Toyota’s hybrid technology, and if so, what of it is related to that used in the Prius?

    • 0 avatar

      Ford’s system is similar to Toyota’s but developed in house.

      They are similar designs, but that is where it stands. Nothing was co-developed and no technical help from either side.

    • 0 avatar

      @Robert.Walter- Wow, I’m surprised that you weren’t aware of the Ford hybrid system’s beginnings. All of your other posts that I have read (at least the historical ones, you lose me on some of the technical stuff) have been on the money.

      I guess I find it surprising that not everyone knows by now that Ford developed their own system. Apparently Toyota’s PR department is way better than anyone else’s! (The last sentence is sarcasm, since you can’t see me laughing as I type this)

    • 0 avatar

      Thanks for the compliment and affirmation. (I was trying to stay fact-based, fair, and limit speculation; I think I may have been the first guy to call damp air and hydroscopic materials as a potential cause of the pedal sticking. Although, admittedly, I didn’t spot the double wedge feature in the CTS spring cap used for pedal hysteresis.)

      Re. the origins of Ford’s hybrid tech., I wasn’t that close to that part of that program, but I do recall that there was a lot of talk of something licensed being portrayed as Ford home-grown.

  • avatar

    +1 for reclusive in nature…roflmao

  • avatar

    The problems are not related at all. They are similar designs and likely will run into similar problems. The differences in how they react are very different. I don’t think there is a possiblity that they are related at all. Both systems were independently developed and are very similar in nature. Toyota didn’t help for and Ford didn’t help Toyota with this.

  • avatar

    Reclusive may have been joking around, but I do wonder if other automakers might get pulled into this.

    Although, as it has been stated above, despite popular misconception, Ford does not license any hybrid tech from Toyota, Nissan definitely has, and to my knowledge, still does. The Altima hybrid, although fairly limited in sales, is pretty much a Toyota hybrid system mated to an Altima gas engine and body, are we going to see the same issues there?

    GMs hybrids seem to have gone a different direction than those of Ford and Toyota, but as the pedal fiasco shows, where GM tried to say there was no problem with Pontiac Vibes despite them being the same exact car as Toyota Matrices, they aren’t exactly the most forthcoming when it comes to this sort of thing.

    • 0 avatar

      I doubt it, the focus of the media and the government is squarely on Toyota. Both the Chevy power-steering investigation and this Ford situation have been largely ignored by most of the media. It would take a really big event to get media attention away from Toyota.

      Also, as far as GM hybrids, most of them are BSA: Belt-Driven Starter Alternator style mild-hybrids which are basically simple start-stop systems so they aren’t very similar by design. GM also has two-mode hybrids in the Yukon, Tahoe, etc that are closer to Toyota/Fords Atkinson-cycle/p-s hybrid design, but the reality is that the reason why this Prius thing became such a big deal is because of Toyota’s other recall woes.

      If Toyota was smart enough to deal with the Prius issue earlier when the DetroitBeareu story broke much like how Ford handled it, this issue would have largely been forgotten like most insignificant recall stories.

  • avatar

    Correct me if I am wrong… but doesnt ford license their hybrid technology from Toyota? If so does ford have the ability to modify what is licensed? I doubt it but still.

  • avatar
    Mr Carpenter

    Nobody’s blamed George Bush for this (yet)….

  • avatar

    We had four or five complete brake failures on our company’s two Ford Escape Hybrids. Without warning the “check brake” warning flashed on, and the chimes went off. It happened to me once and the other driver 3 times. A third driver reported one instance to the boss and we found about it later. In each case the brakes were fully restored after turning the engine off and restarting. These two vehicles were removed from the fleet and the company announced that “our experiment with hybrid vehicles has ended”.

    Google “Ford Escape Hybrid brake failure”. Many others have had the same problem.

  • avatar

    This barrage of techno-baddies makes the Curbside Classic series that much sweeter.

    When the car doesnt work u wish its a Volkswagen.

    Just far too many Electronics and they all end up arbitrarily decided by the Computer, sometimes they received the wong info and acted deviously.

    So as planes that were fly by wire, in a real emergency the pilot can only pray the computer and him were all on the same page.

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