Regen Braking Issue When Turning

[hybridbear]

My FFH acts similarly, Low is not useful for freeway driving because the ICE rpm gets so high. I can't imagine doing that as a gas saving technique. Maybe the FFE works a bit different?? In stop and go traffic it may help.

L in the FFH causes the ICE to race. It will also turn the ICE on if it is off. In the FFE L behaves completely differently. In the FFE L can be used at any time for maximum regen braking, even with a depleted HVB. L will only turn on the ICE in the Energi if you shift to L with a full HVB.

[hybridbear]

On September 30th I'll be meeting with a Ford engineer at our local dealership to take a drive with him in the car to observe what is happening.

[GrySql]

On September 30th I'll be meeting with a Ford engineer at our local dealership to take a drive with him in the car to observe what is happening.

I'd take that as quite a compliment to your OBDII readings & charts, diagnostic skills and persuasive arguments.

 

The Forum strikes again... :superhero:

[hybridbear]

I took a drive with the Ford Engineer today. He is a Ford employee based out of Minneapolis that works with the engineers in Dearborn. He said there are 3 others like him assigned to the Twin Cities area. He had me drive & he recorded three instances of the surge on his laptop.

 

I asked him about the updating of modules & he said that the car is designed for a "coordinated flash" of the modules, so even if a recall, like 15E03, only mentions updating the PCM, he says that IDS will automatically update 8 modules so that the calibration stays in sync. He was unsure which 8 modules they are exactly that are part of that coordinated flash programming.

[corncobs]

Hopefully there will be a fix for this issue soon!

 

I had one pretty bad one the other day and it definitely gets your adrenaline going for the very second it happens.

Edited September 30, 2015 by corncobs

[GrySql]

He had me drive & he recorded three instances of the surge on his laptop.

 

I asked him about the updating of modules & he said that the car is designed for a "coordinated flash" of the modules, so even if a recall, like 15E03, only mentions updating the PCM, he says that IDS will automatically update 8 modules so that the calibration stays in sync. He was unsure which 8 modules they are exactly that are part of that coordinated flash programming.

Having him record 3 instances was a breakthrough, good work HB!!

Learning about the 'coordinated flash' is more excellent info, something we've not heard before.

 

What's the next step from Ford, did the engineer have any idea?

[hybridbear]

What's the next step from Ford, did the engineer have any idea?

He'll send the data off to Dearborn & we'll wait to hear what they say.

[dtw-dave]

The following is what I'm about to post on safercar.gov. Very scary and disappointing series of events with my wife's 2013 Fusion Hybrid. If anyone experienced similar, I would love to hear about it. I will answer any questions that users may post.

 

==========

 

Beginning about January 2015, and occurring about every other month for a total of six incidents, my wife's 2013 Fusion Hybrid (currently with 25,500 miles) experienced what feels like a power surge when making a boulevard left turn. (I experienced this once in this vehicle; the remainder were when my wife was driving.) It is possible that this is related to the regenerative braking system at least in part, as I have seen others describe it as a feeling of hitting an ice patch. The general conditions would include: a) foot on brake; b) decelerating; c) presumably in EV mode [though not necessarily]; d) beginning a left turn [but we believe this is incidental]; e) warm engine; f) less than 30 mph. On October 1, 2015, a new condition caused the feeling of unintended acceleration, as my wife was on a side street near our home when she was approaching a stop sign and felt the power surge, which she states was many times worse than any other instance of this event that she ever experienced. Conditions this time included: a) foot on brake; b) decelerating; c) presumably in EV mode [though not necessarily]; d) straight path [that is, no wheel turns]; e) warm engine; f) less than 25 mph.

 

We took the vehicle to the local Ford dealership the evening of the last incident. Of course they found no codes and no evidence of anything wrong. They tell me that they drove the vehicle a few miles the first day they had it, and about 20 miles the following day and could not duplicate. (Even if they DID duplicate it, their porter was driving it and no codes would be generated, so the result would have been the same.) I also contacted the Ford Customer Relationship Center while it was in the shop to document that we had this problem. They seemed helpful and actually called to follow up the next day but the bottom line is, unless Ford Motor Company and their Engineering community acknowledge a problem and do something to address it, it will forever be a ghost in the machine, with the blame and doubt falling on the vehicle owners, not unlike Toyota's well documented, fatal and shameful unintended acceleration cases.

 

I am concerned about our safety while driving the vehicle of course, but also financially because this is a purchase not a lease, and we intended to keep this car for some time; I would definitely be taking a loss if we decided to sell it. I hope that no one gets hurt or killed while this problem exists and urge Ford Motor Company to get to the root of the issue that myself and other owners are fearfully experiencing.

Edited October 8, 2015 by dtw-dave

[hermans]

See this thread on the subject.

[Waldo]

There's a big difference between unintended acceleration and intermittent regen braking. Not that your issue doesn't need attention and should be resolved, but putting it on the level of Toyota's recalls is a big exaggeration. Sounds to me like what you are experiencing is a blip in the regen braking, basically the regen systems stops working so you suddenly are braking only by the amount that the pedal position will give you out of the service brakes. The solution is simply to push the brake pedal harder, it will engage the service brakes and the car will stop just as quickly as if nothing had happened.

 

This reminds me of when race car drivers say the car "accelerated" when they were sliding off the track and get onto wet grass. The car doesn't really "accelerate", it's just that the human perception of a change in deceleration can be interpreted as an acceleration. It's not, you're still slowing down, just not as much as you were before.

Edited October 8, 2015 by Waldo

[dtw-dave]

I don't know how to merge topics, but I just posted my experience with this issue on my 2013 Fusion Hybrid here at the site (didn't know this thread existed ... sorry, I did check). Reading through all your tribulations and detail hybridbear, I don't know how Ford Engineering can ignore this, and not be able to solve this problem! I am definitely tuned into this thread ... I cannot wait to see it resolved. I hope it is resolved. I have purchased a dozen Fords in the last 30 years, and have a Mustang on my list, but this is definitely shaking my confidence. We love our Fusion, but this is beyond ridiculous ... it's downright dangerous. If it would help to communicate directly, let me know how we can arrange that!

[dtw-dave]

With all due respect Waldo, until you experience it, please don't call it a "blip." My wife drives this car and I don't enjoy the prospect of her getting hurt. On top of that, if she gets into an accident as a result of this, who are you to say that someone can't get killed. Not to mention the additional cost I will incur from my insurance company for having an accident. Yes, this is serious. And yes, this is on the level of Toyota in the sense that Ford is doing nothing about a problem that can injure people. Is the GM ignition switch issue just a hiccup in the air bag system to you?

 

Do you really believe that the "solution" to resolving this problem is to brake harder, on a $35,000 car!? Read through the thread that hermans linked to.

 

Also, I don't know what the problem is, which is why I'm seeking information about it. It feels like acceleration. I'm not an engineer.

Edited October 8, 2015 by dtw-dave

[bdginmo]

Interesting. I just stumbled on this thread and I believe it explains a strange symptom I've noticed, but have largely ignored. In my case I park in a garage while at work. The garage has one of those serpentine ramps to exit so I have a continuous sharp left turn as I descend the floors. I noticed that occasionally the car will feel like it lurches forward almost like it's shifting gears. Naturally I was puzzled by this feeling, but didn't much thought into it until now. This issue is very likely to be what I'm experiencing too.

 

Nice work hybridbear. I have FORScan and would love to be able to reproduce your data. Which PIDs were you using for the wheel speeds? I realize the Ford engineer has already collected the data so it's probably moot for me to do it too, but it's an interesting problem worthy of a learning opportunity for me.

[Waldo]

 

Do you really believe that the "solution" to resolving this problem is to brake harder, on a $35,000 car!? Read through the thread that hermans linked to.

 

 

The solution to the problem needs to come from Ford, the fact that you don't know what it is doesn't mean that Ford isn't working on it. The solution to not causing an accident is to press the brake harder.

 

The fact that this has only happened to you under relatively light braking at low speeds is likely not a coincidence, it's probably a combination of those conditions that triggers the error. Seems to me that under those conditions there is plenty of margin to recover before any kind of collision would occur.

 

Have you seen that story that came out today about the Chinese glass bridge that cracked? The glass was tripple layered and wasn't part of the structure of the bridge in any way, so nobody was ever in any danger, yet panic ensued and everyone feared for their life. In reality the panic was far more likely to cause injury than the actual failure of the glass was.

[jeff_h]

 

The solution to the problem needs to come from Ford, the fact that you don't know what it is doesn't mean that Ford isn't working on it. The solution to not causing an accident is to press the brake harder.

 

I experience this "type" of thing (may be the exact same thing, may be a different issue, so I'll call it the same "type" of thing) almost every morning as I pull into the spot at my company's parking lot; does not seem to have anything to do with acceleration but instead something to do with regen/anti-lock or something related to the way the car reads the feedback from whatever sensors report the speed of each wheel, as it only happens to me when the wheel is turned more than slightly, like turning into parking space as noted above.

 

So dtw-dave does it seem like there is acceleration occurring, or a change in the way the braking is occurring where there seems to be a gap/lapse in the braking when you expect the braking resistance to be constant? That's what the feeling is for my car, that there's a temporary lapse in the braking resistance and if not prepared for it, the driver can be caught by surprise.

 

Like Waldo noted, it's probably something that engineers are already working, so if you submit the above to safercar.gov it probably wouldn't be the first time someone has.

[dtw-dave]

Waldo; I don't need your condescending anecdotes. Please stop talking. You are approaching troll status. Tell that to a pedestrian that gets nailed by one of these vehicles because someone couldn't react fast enough to "brake harder."

 

jeff_h, it feels like acceleration. But I'm just learning about what others experienced after I posted. Based on other experiences, it seems it is related to the regenerative braking. Most times it was noticed by my wife on a left turn, but when it occurred on a straight stop that raised a red flag. I'm going by my wife's description, though I experienced it once in a turn. I do indeed hope that the engineers are working on it. By this time and hybridbear's data, one would expect them to be. I did submit to safercar.gov.

 

I consider this serious and I'm trying to make some noise to see if anyone at Ford is listening.

[murphy]

I can duplicate this "feeling" at will. Very close to an intersection with a stop sign is a manhole cover that is in line with my left front wheel and is considerable lower than the road surface. When my left front wheel hits the manhole cover all braking stops until the wheel drops down and regains traction. I am well past regen because I am only about 10 feet from where I must be completely stopped. I don't think the car is accelerating but the immediate lack of braking makes it feel like acceleration. I don't know if it matters but my car is in L when this happens. Now I guess I have to go test it while in D.

[Cobra348]

I can duplicate this "feeling" at will. Very close to an intersection with a stop sign is a manhole cover that is in line with my left front wheel and is considerable lower than the road surface. When my left front wheel hits the manhole cover all braking stops until the wheel drops down and regains traction. I am well past regen because I am only about 10 feet from where I must be completely stopped. I don't think the car is accelerating but the immediate lack of braking makes it feel like acceleration. I don't know if it matters but my car is in L when this happens. Now I guess I have to go test it while in D.

There is a reasonably steep hill on one of the city streets here. I use it to recharge the HVB by using ACC to control my descent, thus kicking in regen. One area is as you describe ... the pavement drops off and then rises again. If I guide around that spot, nothing happens, but if I hit it during the regen run, I get the same feeling and in fact the traction control light comes on and off quickly.

 

It does feel as if it is unintended acceleration but it is the lack of traction for a fraction of a second. I can reproduce it very easily ... and it's a straight run ... no turning needed to reproduce.

[hybridbear]

I don't know how to merge topics, but I just posted my experience with this issue on my 2013 Fusion Hybrid here at the site (didn't know this thread existed ... sorry, I did check). Reading through all your tribulations and detail hybridbear, I don't know how Ford Engineering can ignore this, and not be able to solve this problem! I am definitely tuned into this thread ... I cannot wait to see it resolved. I hope it is resolved. I have purchased a dozen Fords in the last 30 years, and have a Mustang on my list, but this is definitely shaking my confidence. We love our Fusion, but this is beyond ridiculous ... it's downright dangerous. If it would help to communicate directly, let me know how we can arrange that!

I merged the topics. I also hope that Ford will figure out how to fix this!

 

Nice work hybridbear. I have FORScan and would love to be able to reproduce your data. Which PIDs were you using for the wheel speeds? I realize the Ford engineer has already collected the data so it's probably moot for me to do it too, but it's an interesting problem worthy of a learning opportunity for me.

I was using Torque Pro so that I could log data from multiple modules. In FORScan I think the wheel speed sensors are in the Body Control Module. You can log all the rest of the data from the BECM to see what happens, without the wheel speed data.

[bdginmo]

I was using Torque Pro so that I could log data from multiple modules. In FORScan I think the wheel speed sensors are in the Body Control Module. You can log all the rest of the data from the BECM to see what happens, without the wheel speed data.

 

Thanks. Yeah, I found them. I was just getting ready to ask how you log PIDs from two different modules simultaneously in FORScan, but it appears that is one limitation. I'll try out Torque Pro. Oh, and the problem didn't happen while leaving the parking garage today. Typical...when you want it to happen it doesn't...figures.

[corncobs]

I can duplicate this "feeling" at will. Very close to an intersection with a stop sign is a manhole cover that is in line with my left front wheel and is considerable lower than the road surface. When my left front wheel hits the manhole cover all braking stops until the wheel drops down and regains traction. I am well past regen because I am only about 10 feet from where I must be completely stopped. I don't think the car is accelerating but the immediate lack of braking makes it feel like acceleration. I don't know if it matters but my car is in L when this happens. Now I guess I have to go test it while in D.

Same here I can also reproduce this almost at will. It's definitely a strange feeling but it's for sure not accelerating its "just" cutting the regen which makes it feel like it.

 

It's much easier when you have different road surfaces (like Murphy's example) or when the road is wet.

 

And yes this shouldn't happen and Ford will come up with a fix.

[lolder]

Two steps forward, one back. Except in the case of FFH Gen1 vs, Gen 2 its the other way around. The brakes on Gen 1 are flawless. How can this happen?

[murphy]

Two steps forward, one back. Except in the case of FFH Gen1 vs, Gen 2 its the other way around. The brakes on Gen 1 are flawless. How can this happen?

Now that you mention it I drove a 2010 FFH for four years and never encountered this "feeling" while approaching a stop.

[murphy]

I can duplicate this "feeling" at will. Very close to an intersection with a stop sign is a manhole cover that is in line with my left front wheel and is considerable lower than the road surface. When my left front wheel hits the manhole cover all braking stops until the wheel drops down and regains traction. I am well past regen because I am only about 10 feet from where I must be completely stopped. I don't think the car is accelerating but the immediate lack of braking makes it feel like acceleration. I don't know if it matters but my car is in L when this happens. Now I guess I have to go test it while in D.

Having "slept" on the problem I have an explanation.

 

Regen braking is applied by a motor/generator that is connected to the shaft that feeds the differential. For regen braking to work, both wheels must be in good contact with the road. If one wheel is off of the ground no force can be applied to the road and thus no braking. Lets take the limit case where the motor generator is locked and can't turn at all. With the car moving with one wheel off of the road the wheel in contact with the road will send rotation to the differential. The shaft to the motor can't turn so the rotation is applied to the shaft for the wheel that is off of the ground by the differential and that wheel turns backwards. No stopping force is possible while one wheel is off of the ground. The car should detect this as one wheel sliding on ice and terminate regen braking and initiate ABS braking. It is obvious that when I said, above, that I was well past regen braking I was wrong. Regen braking is applied to both wheels equally and is not compatible with ABS braking which is applied to individual wheels. For ABS braking to work on the front wheels the eCVT has to basically be in neutral.

 

I need to lean heavier on the brake pedal when I get to the manhole cover.

 

Update: I have now crossed the manhole cover with friction braking definitely in effect. The "feeling" does not happen at all. The friction braking prevents the wheel that is in the air from turning at all so the three wheels that are on the ground provide braking.

Edited October 11, 2015 by murphy

[Texasota]

The brakes on Gen 1 are flawless. How can this happen?

Anytime software is enhanced/modified unexpected things can happen. I worked in this field for 31.5 years and it never ceased to amaze me how faithful the law of unintended consequences is.

Edited October 9, 2015 by Texasota