Grabby Brakes?

One thing I've noticed with the cooler weather and aging battery pack where I frequently only have a couple regen bubbles available, is that the brakes now often get grabby at higher speeds.

Descending a slight hill at moderate speed, often it becomes difficult to modulate the brakes, similar to grabby brake syndrome at low speeds, though not as bad.

drees said:

One thing I've noticed with the cooler weather and aging battery pack where I frequently only have a couple regen bubbles available, is that the brakes now often get grabby at higher speeds.

Descending a slight hill at moderate speed, often it becomes difficult to modulate the brakes, similar to grabby brake syndrome at low speeds, though not as bad.

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Exactly the behavior I was seeing. Try the remedy that I tried (a few posts up). It has worked wonders. And actually even though I said "15mph and below", I need to revise that to 30 or even 40mph and below. I guess I hadn't realized it was so bad until after I applied the remedy and noticed that my old behavior was no longer necessary. For example, I was getting grabby brakes while decelerating on exit ramps from highway speed and had adjusted my braking behavior to compensate--basically avoiding a "light" touch on the brakes, where the grabbiness was worst. Now I am noticing that that is no longer necessary. As I decelerate on the exit ramp I am EXPECTING grabbiness, but it's simply not there. I am still amazed.

I have a 2012 and have no such "chronic" grabby brakes as other posters have. Very rarely, I will experience an "episode" lasting about 10 seconds where touching the brake causes a severe braking action. But, I have learned I can reset it by taking my foot completely off the break and then braking again.

I live in California where the temp is between 50 and 90 most of the time, so could grabby brakes be a symptom of the system getting to cold??

Also, I have no loss of regen bubbles, and two missing bars of capacity (just lost the second one today)

The Grabby brakes at low speeds are are my main complaint with my 2013 leaf. My lease is just about up and the brakes drove my decision to return the car rather than buy it. Love the car, hate the brakes. I reset them regularly and have had the dealer look at it a few times, problem always returns after a few days. I have moved on, the leaf goes back to the dealer in a few weeks.

Transtead said:

I have a 2012 and have no such "chronic" grabby brakes as other posters have. Very rarely, I will experience an "episode" lasting about 10 seconds where touching the brake causes a severe braking action. But, I have learned I can reset it by taking my foot completely off the break and then braking again.

I live in California where the temp is between 50 and 90 most of the time, so could grabby brakes be a symptom of the system getting to cold??

Also, I have no loss of regen bubbles, and two missing bars of capacity (just lost the second one today)

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In my case both symptoms (grabby brakes and loss of regen bubbles) occur, or get worse, when cold. Although my loss of regen bubbles is noticeable even in moderate (50-60 degrees) temps. I really only get full bubbles any more when high 60's or higher and battery is less than half full. In colder temps (30's & 40's) I'm only getting 1 bubble until battery is down to 8 bars, 2 bubbles down to 4-5 bars and then 3 bubbles after that. I'm not a huge fan of regeneration normally, but when it traffic I am probably missing out on a lot of regen.

At the risk of going slightly off topic, my regen bubble report from this morning is thus:

Outdoor temp: 21F
Pack temp: 53F

I had ZERO regen bubbles until I was at 3 bars, and 9 miles on the GOM. At the point I finally got the first bubble, LEAFSpy reported SOC at 35%.

Okay, a caveat or two: I was travelling along the highway at 70mph keeping the pack plenty cool, and besides, you don't need regen in that situation anyway. I did get my first bubble at 9 miles/3 bars a couple miles before my exit. Once I slowed down, the pack temp increased quickly and I got more bubbles. A few miles later as I was approaching my destination the pack temp had risen to 59F and I had 3 bubbles (out of 4). I was down to 2 bars at that point.

lpickup said:

At the risk of going slightly off topic, my regen bubble report from this morning is thus:

Outdoor temp: 21F
Pack temp: 53F

I had ZERO regen bubbles until I was at 3 bars, and 9 miles on the GOM. At the point I finally got the first bubble, LEAFSpy reported SOC at 35%.

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Yep, that's precisely the behavior I get in winter since the P3227 update. I can only surmise that Nissan was seeing significant plating of elemental lithium onto the cathode during cold-temperature charging to warrant such a drastic reduction in regeneration.

But the P3227 update is not directly related to grabbiness of the brakes. That issue was addressed by "PX65AA Recalibration" according to the paperwork for my 2011 LEAF. That said, I find that grabbiness tends to be much worse when there is rust on the brake discs. Since the P3227 update for the battery, we find we need to apply the brakes much more often, so that does tend to Reduce the grabbiness somewhat.

Wow, 30 pages on this ... on my '12 with about 36K miles and moderate (Midwest) climate the only thing that gets annoying at times (very intermittent, goes right away once we get moving again) would be when in lots of stop and go traffic and the brakes will 'grab' like you stomped on them but have only hit them lightly --- I've learned to live with it so I can avoid the 'head bob' scenario with passengers on board; like I said it doesn't occur frequently. This almost looks like it may get worse over time; hasn't over the last several months (at least in my driving scenario) so we'll see ... where the LEAF has a lot of benefit is through its regen aspect so would almost like to be able to dial in more it to avoid even touching the brakes in stop & go traffic; of course you might need to avoid it as the car behind you isn't paying attention that you're slowing down w/o using the brakes (I think that BMW iseries and Tesla don't have this issue) but making the regen 'adjustable' could be a solution here; probably not feasible with the early years but perhaps something Nissan has looked at?

I definitely noticed the grabby brakes on my 2011 but the problem seems to be gone in the 2016.

There is something on 2014 Leaf.

I think I may have found the solution...

Replace your 12v battery (the "regular" car battery in the front engine bay).

I had the same issues as people described in the numerous posts here. I would characterize it a bit differently however. To me, it felt like whenever I brake, the regen braking would kick on and off. This would cause moderate to severe jerking of the car when coming to a stop. I tried all the solutions posted here with little success (turn off traction control, release braking, etc., update software). The issue would always return.

Desperate for a solution, I took it to the dealership AGAIN and explained what was happening (for the fourth time, now out of warranty). This time the only "code" to show up was for an old low voltage fault of the 12v battery. Luckily, the dealership tech I got this time had seen this issue before, and as weird as it sounds, told me that the 12v battery effects the brake controller. I have a 2012 Leaf, so around 4 years is about how long a car battery lasts in normal cars.

Since replacing the battery (you can do it yourself for around $100) I have not seen this issue return. Hope this helps.

The 12V battery is well worth a try. My Prius did some weird things when it went after changing it everything was back to normal. I'll put one on the Leaf at the weekend and let you know....

I just resolved my grabby brake issue, which was becoming borderline dangerous in stop and go traffic. When taking it for service, they addressed a brake related recall, however when reading up on the recall it appears its not specifically for grabby brakes (Recall Number: 16V119000). I read on here about replacing the 12v battery as being a resolution and I did that as well. No more grabby brakes after receiving these two services. I think the 12v battery replacement was what did it, as I've also observed my car not starting (T/M System Malfunction Error) which was due to failing 12v battery. Lesson learned, make sure 12v battery is healthy as this affects more than just powering basic accessories. It's been such a relieve, now that I don't have to deal with annoying grabby brakes anymore.

Can someone post all of the steps needed when replacing the 12V battery please?

2012 leaf with hosed battery at 7 bars.

Just adding how i solved the grabbing/releasing brakes in cold weather and low to no regen...
check your front brake pads!I started noticing what i considered dangerous braking where pressing the brakes would result in a sudden release of braking as if i let off of the brake pedal. This would sometimes lead to a sudden grab of the brakes as i tried to compensate...
so it would be this crazy brake no brake situation where i could not have a smooth braking.

I checked the battery and gave it a good three hour 10 amp charge, nothing changed!
I checked my front brake pads and saw about half the pad was there so i decided to replace the front pads with ceramic type pads.
So far i have not experienced the crazy braking!
I do feel the computer ease up on braking sometimes but nothing like the catastrophic feeling i had before.
so im guessing the TSB fixes some aspect of braking but there still is a oversight for brake pad wear and cold weather/ low regen.

just my two cents and i hope this helps.

I find it interesting that these "normal" ICE vehicle problems are hidden by our car.

In an ICE vehicle, if your battery dies, you can't start it. So there are early signs of "low battery" or even a battery level indicator. In an EV, this is hidden, because only periphery systems use an "external" battery - and probably for redundancy.

In an ICE vehicle, your brake pads wear much faster, and you can feel your breaks "go out" well before. In an EV, the regenerative braking can do most of the breaking so you don't really "feel" it until your car shifts over to manual breaking.

My 2012 is starting to feel it's age - but I still love it.

I wish there were more EV mechanics out there, though. I don't want to take it to the dealership, because they don't care about my EV too much - they don't make money on us.

Transtead said:

I find it interesting that these "normal" ICE vehicle problems are hidden by our car.

In an ICE vehicle, if your battery dies, you can't start it. So there are early signs of "low battery" or even a battery level indicator. In an EV, this is hidden...

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Very true and it's unfortunate because a self-diagnostic function could easily and cheaply be built in to the vehicle. Useful and inexpensive digital battery-testers can check not just voltage but capacity as well. EVs would do well to build such circuitry into the car so that the owner can be alerted to a weakening 12V battery before it progresses to where other subsystems are affected. It boggles my mind that this isn't done as a matter of course.

i've had some grabby brakes that i feel are caused by the response time of the electric motor in the master cylinder. Never had anything like this on any car (ICE or EV) with a vacuum brake booster.

On an old 2012 down to 8 cap bars there is little to no regen braking. If you let off the throttle to coast toward a redlight, then need to add a little braking to slow, then on the second application of the brakes it will nearly lock the car up to a stop with just the slightest of foot pressure on the pedal.

nlspace said:

i've had some grabby brakes that i feel are caused by the response time of the electric motor in the master cylinder. Never had anything like this on any car (ICE or EV) with a vacuum brake booster.

On an old 2012 down to 8 cap bars there is little to no regen braking. If you let off the throttle to coast toward a redlight, then need to add a little braking to slow, then on the second application of the brakes it will nearly lock the car up to a stop with just the slightest of foot pressure on the pedal.

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Have you tried the "recalibration procedure"?

I have grabby brakes in the Leaf I have just bought, creeping along in traffic in eco mode seems to show it at its worst.
I'll try a few things independently and see what I find; traction control off and brake depress for 30 seconds, 12v battery check/replace, brake pad and fluid check/replace.