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Post by Feng on Mar 25, 2015 13:03:08 GMT 11
Last week when I rolled out of my driveway, I gently braked and the car ended up lurching to a halt instead. Has anyone else had this happen before? There's a service bulletin overseas for LEAFs of similar vintage which describes the same problem with low speed braking and a software fix to correct that. I might ask about it when I get my car serviced in a few weeks: www.electricvehiclewiki.com/?title=File:NTB12-086_grabby_brake_fix.jpg
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Post by Phoebe on Mar 25, 2015 13:35:55 GMT 11
Not sure. Will watch out for it.
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Post by lesmando24 on Mar 25, 2015 18:40:49 GMT 11
Yes, that is a very old issue which was never fixed on the Australian models. The software fixes for the U.S.A. don't map very well to the Australian version as it is between models over there. Mine will do it when in stop start traffic. Usually when you push on the brake, then partial lift off and apply it again. But I have got used to it and lift off completely, or feather very gently. I have also had it not apply the brakes enough when first starting the car, the pedal feels hard and you have to mash it down hard to get feeling (it does work tho, but more foot needed from me). I turn the car off and on again and it is OK.
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Post by Feng on Mar 25, 2015 18:45:47 GMT 11
I've given details to Dean about it, he said he'll pass it on to the technical team at Nissan HQ to look at. See if anything comes of it!
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Post by leafboi on Mar 26, 2015 10:19:11 GMT 11
I've experianced this also. They grab is very unexpected and generally at low speeds. It sure stops the car in its tracks.
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Post by eburbsleaf on Mar 27, 2015 22:31:42 GMT 11
Same here - have it occaisionally generally first thing in the morning and yes its quite grab-by.
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Post by richardh on Mar 29, 2015 13:23:09 GMT 11
If this brake problem needs a software upgrade then it might be a way to force Nissan to release the upgrade in Australia.
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Post by philcanberra on Mar 31, 2015 23:45:25 GMT 11
Yes. I've had this quite a few times. I found out by turning the car off and on again it would fix the problem. But that's no good when you're at a set of lights, so I found by putting the car in reverse then Drive really quickly also fixes the problem.
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Post by philcanberra on Mar 31, 2015 23:46:52 GMT 11
I've given up all hope on Nissan Australia to EVER provide software updates. I'll see if there's a way to upload the software updates myself...
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Post by Feng on Sept 10, 2015 18:23:13 GMT 11
My brakes did something scary yesterday: When a car in front of me was about to turn into a side street I tapped on my brakes to lose some speed before changing lanes. The car ended up slamming almost to a halt with the ABS doing its thing. The scary part was my foot was already off the brake pedal and it was still braking hard for about a second afterwards. I almost got rear ended as a result, the car behind me must have thought I was overreacting badly. I was a bit shaken up after that. The car's brakes were being a bit sensitive all day especially when almost coming to a stop. I kept apologising to my boss who was in the car with me for the jerky braking. Last night I read up on it and someone on the MNL forum suggested the following steps to recalibrate the brakes: 1) Turn on car and turn off the traction control (button on left side of driver) 2) Put in ECO (D might work too but I didn't try) 3) Drive forward a little 4) Press the brake pedal slowly and very firmly 5) Hold pedal down firmly for a good 30 seconds 6) Drive around the block to test 7) Put traction control back on I did it last night and did a few test stops around the block. So far the car is behaving like normal again. When I got the car serviced today they couldn't find any problems with the braking system and the 12V battery tested okay. If anyone else is experiencing grabby brakes they might want to try the steps above and see if it helps.
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Post by mike on Sept 10, 2015 20:48:42 GMT 11
Feng...I had a very similar experience a few months ago. Traveling in rush hour traffic, I got a bit distracted and saw taillights come on in the car ahead. I jumped on the brake hard and immediately released the car in front wasn't braking hard. I took my foot completely off the brake, but my Leaf continued to brake hard for another second, slowing from 90km/h to about 30km/h. The cars behind me were not impressed by my sudden and unwarranted speed reduction. Luckily, I didn't get rear-ended. When I get my Leaf back from the body shop, I'll try your suggestion.
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Post by markrmarkr on Sept 11, 2015 9:37:02 GMT 11
I've seen this a couple of times too. It really gave me an adrenalin rush each time. I think Nissan just hasn't got the balance right for all the stuff that effects the brakes:
eco or D traction control ABS Fully charged
I've formed the theory that the car has some kind of memory which is at the heart of this problem. The car expects you to be doing the same thing all the time, and adapts it's behaviour to the way you drive. Normally this works well, but in certain circumstances it can be a problem. I think it can be confused first thing when you turn the car on - memory empty to start. Memory may also be confused if you brake hard and then normally, or vis-versa. This is compounded by the list of things above which can all effect the way the car brakes.
IMHO.
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Sept 11, 2015 15:07:59 GMT 11
Has anyone tried holding onto the ebrake? The leaf beeps then Applies the rear? brakes.
I should try this one day on the bmw
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Post by Jim Hare on Sept 11, 2015 16:18:41 GMT 11
Yep, definitely happened to us, somewhat regularly, like once every two weeks or so. Nothing severe like you experienced Feng, just much more braking than we were applying.
Seems like this would be a recall situation as opposed to a minor issue. Hope Nissan take it seriously!
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Post by gabzimiev on Sept 12, 2015 12:46:21 GMT 11
the design idea was its a safety feature added to new cars to deal with older drivers. since ABS was brought in they found that older drivers attempted to pulse the brakes manually (I’ve never driven a car without ABS) meaning that the brake system didn't work fully. so they now guess at when your emergency braking and apply full force, regardless of if you remove your foot to pulse.
by the sounds of it it has a bad time guessing.
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Post by rusdy on Jun 13, 2016 0:30:48 GMT 11
Hmmm... This brake problem is more common than I thought. Mine is pulsating (I saw it in the energy monitor) and grabby in the last couple of days. It doesn't regen to 30kW anymore either unless it's low charge (5 bars or less).
I thought it's the 'cold' days (perth cold that is) that caused it. I'll try the recommendation above (turning traction control off thingy)
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Post by duncan on Jun 16, 2016 20:34:20 GMT 11
Ours are really grabby (ie poor progression in light braking) and have been for some time. After a software update at last service it was better but return to normal (ie poor) within a few days.
It is sure to be a software calibration problem because the brakes downstream from the master cylinder are a very conventional hydraulic system, it's all about how the super dooper master cylinder reads your input and decides what % of the pressure to apply to the hydraulic system
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Post by jake on Jun 17, 2016 1:31:56 GMT 11
Ours are really grabby (ie poor progression in light braking) and have been for some time. After a software update at last service it was better but return to normal (ie poor) within a few days. It is sure to be a software calibration problem because the brakes downstream from the master cylinder are a very conventional hydraulic system, it's all about how the super dooper master cylinder reads your input and decides what % of the pressure to apply to the hydraulic system The brake management software is not perfect in the Leaf. It is definitely a little bit glitchy. Especially noticeable when trying to brake at low speeds or after an emergency brake. Symptoms I've noticed are. Over sensitive at low speeds, brake not being released immediately after an emergency brake, and an unintended release of the brake when transitioning from regenerative braking to using the disk brakes. Most problems go away after a restart or a firm application of the brake while stationary. They may have made some improvement with the last software update, but problems still exist. Still, nothing I can't live with. Generally I love having sensitive brakes.
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Post by rusdy on Jun 17, 2016 15:28:35 GMT 11
The pulsating AND grabby issue on mine is fixed after doing the above recommendation (traction control off thingy, as per original forum said, "I have no idea why it worked, but it worked!!").
The regen limits not fixed though. Still only can regen to 20-ish kW (instead of 30kW) when the battery is not under 7-bar or so. I'm guessing the software is now limiting the regen due to some battery degradation (pure guess here).
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Post by jake on Jul 2, 2016 1:44:42 GMT 11
With the last software update, brake regeneration was reduced at high level of battery charge to help the longevity of the battery.
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ant
EV Enthusiast
2012 Leaf, EV enthusiast, AEVA WA Secretary
Posts: 43
LEAF OWNER?: Yes
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Post by ant on Jul 27, 2016 1:28:37 GMT 11
I've experienced this quite a few times, today almost had someone ram the back of the car - they were following too close and the brakes grabbed.. close. Why on earth does Nissan ignore it's customers!?
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Post by hieronymous on Jul 27, 2016 11:30:09 GMT 11
I've experienced this quite a few times, today almost had someone ram the back of the car - they were following too close and the brakes grabbed.. close. Why on earth does Nissan ignore it's customers!? Hi ant There are a few situations which are unavoidable, such as the on-ramp driver who ran out of space but just kept booting it and rammed his/her way into the left lane I was in recently - the nearest car went sideways trying to avoid a collision, and the next 3 drivers including me had to take quite violent evasive action including heavy braking, across 2 lanes. All ended well, but the point I want to make is that for me, that situation is a rarity, and in my 2-year ownership of my Leaf the first time I have had to brake heavily. I put that down to my driving style which is to use the road as if I have no brakes - I keep at least double the recommended spacing between me and the car in front, and as a consequence, regen is almost always enough on its own to slow the Leaf as required. So my suggestion to you is that if you are being tailgated that you immediately slow down to increase the stopping distance in front of you so you can rely on regen only - tailgaters are only a problem if you are also too close to the car in front of you. Nissan isn't going to redesign and retrofit our Leaf brakes, so we have to adjust our driving to suit the conditions including what we know about the Leaf braking performance.
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ant
EV Enthusiast
2012 Leaf, EV enthusiast, AEVA WA Secretary
Posts: 43
LEAF OWNER?: Yes
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Post by ant on Jul 27, 2016 13:10:17 GMT 11
I've experienced this quite a few times, today almost had someone ram the back of the car - they were following too close and the brakes grabbed.. close. Why on earth does Nissan ignore it's customers!? Hi ant There are a few situations which are unavoidable, such as the on-ramp driver who ran out of space but just kept booting it and rammed his/her way into the left lane I was in recently - the nearest car went sideways trying to avoid a collision, and the next 3 drivers including me had to take quite violent evasive action including heavy braking, across 2 lanes. All ended well, but the point I want to make is that for me, that situation is a rarity, and in my 2-year ownership of my Leaf the first time I have had to brake heavily. I put that down to my driving style which is to use the road as if I have no brakes - I keep at least double the recommended spacing between me and the car in front, and as a consequence, regen is almost always enough on its own to slow the Leaf as required. So my suggestion to you is that if you are being tailgated that you immediately slow down to increase the stopping distance in front of you so you can rely on regen only - tailgaters are only a problem if you are also too close to the car in front of you. Nissan isn't going to redesign and retrofit our Leaf brakes, so we have to adjust our driving to suit the conditions including what we know about the Leaf braking performance. I already leave a huge space in front of me - this is partly due to being an expat South African ( frequent carjackings and muggings at traffic lights so you leave space in front of you in order to manoeuvre out when necessary ) and also due to being a naturally cautious driver. On the highway, I leave as many car lengths as speed / 10 - ie. 80 km/h = 8 car lengths. Nissan have a firmware fix for other countries, this post is in the "grabby brakes" thread, there is an existing issue and I was bemoaning this fact. The Leaf regen is so pathetic ( I had an iMiEV before which actually worked ) that only using regen to slow down is not an option - the braking effect in a Leaf is almost imperceptible. Nissan know of the issue, have fixed it in other countries, I would expect them, given this is a potentially dangerous flaw, to fix it. My driving style is what prevented me being rammed and while I'm glad you drive cautiously, please don't assume I don't - so no adjustments necessary, thank you.
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Post by hieronymous on Jul 27, 2016 13:53:33 GMT 11
Hi ant
I see that on MNL (July) there are continuing posts about owners experiencing this issue, so I don't believe it has been fixed - certainly Nissan don't communicate directly with owners (until maybe they are forced into a recall).
As far as I know we have identical cars, and regen on mine is very effective, so either your brakes are faulty, or your Leaf is often fully charged when regen is much reduced.
As for my other suggestion, given my 50 years of driving without being rammed or causing an accident, simply by anticipating other driver's behaviour and applying counter-measures, you can call it "cautious" driving if you like; to me it's a "no-brainer" that everyone else on the road is a potential missile coming my way, and to drive accordingly.
It's a given that you won't get any joy from Nissan; the rest is up to you...
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Post by rusdy on Jul 28, 2016 11:30:20 GMT 11
Hi ant I see that on MNL (July) there are continuing posts about owners experiencing this issue, so I don't believe it has been fixed - certainly Nissan don't communicate directly with owners (until maybe they are forced into a recall). As far as I know we have identical cars, and regen on mine is very effective, so either your brakes are faulty, or your Leaf is often fully charged when regen is much reduced. As for my other suggestion, given my 50 years of driving without being rammed or causing an accident, simply by anticipating other driver's behaviour and applying counter-measures, you can call it "cautious" driving if you like; to me it's a "no-brainer" that everyone else on the road is a potential missile coming my way, and to drive accordingly. It's a given that you won't get any joy from Nissan; the rest is up to you... Going off-topic, my regen is also getting less effective. At first, it never reached 30kW unless the battery is low (i.e. 4 bars or less). Now, after service (oh I wish I never service it in the first place ), i.e. software update, my regen is really really bad (15kW, and maxed out at 20kW at low-ish speed). My guess: the Leaf's software limit regen depending on 'Health' value of the battery, as I've noticed the regen completely changed couple days after service, i.e. (see attachment, how my 'Health' drop to the cliff due to 'software adjustment'): Oh, the regret sending it to service... . In Nissan's defence, Original Manufacturer know their car best (I have my doubt), therefore: - Now I've noticed for the first time, BRAKE DUST (thanks to no high regen) --> so that they sell more brake pads?; - The current sensor goes negative (the hall sensor that sense the battery current, from LeafSpy) when idling (go figure); Now I feel better after ranting
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Post by EVangelist on Jul 28, 2016 19:25:55 GMT 11
Going off-topic, my regen is also getting less effective. At first, it never reached 30kW unless the battery is low (i.e. 4 bars or less). Now, after service (oh I wish I never service it in the first place ), i.e. software update, my regen is really really bad (15kW, and maxed out at 20kW at low-ish speed). We'll be taking our Leaf for its next service in October, were you advised that a specific s/w update was done? If so we will ask them to not do it!! High regen is one of the things I really like about the Leaf, I absolutely don't want Nissan to neuter it.
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Post by EVangelist on Jul 28, 2016 19:29:14 GMT 11
The Leaf regen is so pathetic (I had an iMiEV before which actually worked ) that only using regen to slow down is not an option - the braking effect in a Leaf is almost imperceptible. To date with my Leaf (20 months), 37% of the energy used has come from regen. I consider that to be quite amazing. My Leaf will slow down going down a hill due to regen, the hill needs to be quite steep for it to maintain speed or speed up. However, maybe that's because I haven't had the latest software update?!
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ant
EV Enthusiast
2012 Leaf, EV enthusiast, AEVA WA Secretary
Posts: 43
LEAF OWNER?: Yes
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Post by ant on Jul 28, 2016 19:38:17 GMT 11
The Leaf regen is so pathetic (I had an iMiEV before which actually worked ) that only using regen to slow down is not an option - the braking effect in a Leaf is almost imperceptible. To date with my Leaf (20 months), 37% of the energy used has come from regen. I consider that to be quite amazing. My Leaf will slow down going down a hill due to regen, the hill needs to be quite steep for it to maintain speed or speed up. However, maybe that's because I haven't had the latest software update?! That's interesting - how do you determine how much energy you're getting from regen? Is it the indicator I have highlighted below? I never get more than 3 circles filled while coasting to a stop on regen
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Post by EVangelist on Jul 28, 2016 19:56:18 GMT 11
That's interesting - how do you determine how much energy you're getting from regen? Is it the indicator I have highlighted below? I never get more than 3 circles filled while coasting to a stop on regen Regen rate is not displayed, I calculate it from the Carwings stats, which reports how many kWh was generated for each recorded 'trip' (which is from when you turn the car on to when you turn it off) as well as total kWh used and net kWh used (which is total minus regen). Divide regen by total to get the regen rate. See this thread for the gory details.
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Post by hieronymous on Jul 28, 2016 20:45:48 GMT 11
Going off-topic, my regen is also getting less effective. At first, it never reached 30kW unless the battery is low (i.e. 4 bars or less). Now, after service (oh I wish I never service it in the first place ), i.e. software update, my regen is really really bad (15kW, and maxed out at 20kW at low-ish speed). We'll be taking our Leaf for its next service in October, were you advised that a specific s/w update was done? If so we will ask them to not do it!! High regen is one of the things I really like about the Leaf, I absolutely don't want Nissan to neuter it. I did an MNL search for "software update regen" - 134 posts mainly implicating the P3227 update for regen loss following the update. My Leaf had it last service without any prior advice . I only found out when my AHr and SOH increased by about 2%, rang the dealer and had them read off the service sheet.
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