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Brake Failure

33704 Views 167 Replies 45 Participants Last post by  srichards
Hi all,

Brief history first I have been a Leaf owner for 4 years and my second one has just gone back as the PCP had run its course. I was a leaf Ambassador during the earlier years (hi people if you remember me from Maine road) and up till 30th April I would have told everybody I spoke to how brilliant they are. I am deliberately posting this as a new thread as I find adding to existing just means facts get confused and lost.
On the 1st May whilst in a queue of traffic I rear ended the car in front because my brakes failed completely.
The only reason I stopped was because I hit it . 30 seconds earlier I was doing 70 on the motorway.
The brake pedal just went to the floor and nothing happened other than the ABS system apparently kicking in as I could feel the brake pedal vibrating under my foot.
The incident has now been reported to DVSA. and I would encourage others who have experienced similar to do the same.
The response from Nissan has been less than satisfactory. I would have been happy to help in any way but they have not spoken to me.
I note the other instances on threads of similar things happening and I can only say that this SHOULD NOT BE POSSIBLE. Its a car and it should have brakes that work ALL the time.
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Yeah I never saw that video. My guess is it was removed.
My SO will not let me buy an older gen Leaf after hearing about this so, it has ready affected me in one way lol.
A braking system should not be affected by a bumpy road at any rate
It's not, in my experience. However I do have a late 2016 model. But never had an issue with braking on bumps personally, nor had the ABS kick in either - hopefully it will stay that way!
The car does feel a lot heavier than a fiesta though. Mainly because it is.
Exactly the same happened to me! with a Leaf 2016 and dealer insist there is nothing wrong with the car even when I replicated the issue leaving the parking lot. I took pictures and have video of the car break pedal slammed against the car floor and I have the video of my pumping the break and no stop of the pedal: I have called nissan reported to the NHTS agency and nothing any idea on how to proceed here? Should someone get killed so that this corporation will assume ownership of this problem?


I am in the same boat, I have a 2015 Nissan Leaf Tekna and have had no problems with the car apart from I have just had the same happen the other day, after a run at about 60mph on a warm day (last Sunday) i hit the brakes to slow down at a junction and total failure of the brakes :eek::eek::eek:, i felt the same at the bottom of the peddle almost like the ABS was working it was really scary, luckily there was nobody in front of me else I would have also had an accident, round the next bend the brakes worked as normal :confused: I have lost confidence in the car, we have 3000 miles left and 2 weeks left before it goes back I dont think we are going to be paying any mileage as we dont trust the car.

It should be on my dashcam Ill try and dig out the footage

The cars going back to RCI at the end of this month and we wont be getting another one. @NissanGB
ppen to
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Hi there,

This is Paul who made the original post. Thanks for sharing your experience. I know its a shock when it happens. This sound exactly like what happened to me.
Like you I could not bring myself to drive the vehicle afterwards but fortunately my car was bought on contract which had nearly run its course and i was able to return it to the finance company but not without loss as I did not use it for the last 6 weeks of the term.
I dont think you are in the UK? We have the DVSA in the UK and I am happy to give you the name and email of the guy dealing with my case and also others here in the UK. I am sure he wont want to be bothered with something he cant directly influence but the more cases he knows about the better as far as I am concerned.
My car is allegedly in the possession of Nissan UK who are carrying out research to see if they can identify the cause of the failure. They have apparently bought it back off RCI. Hopefully this sets a precedent we can all pursue if it happens thereby encouraging Nissan to sort it out. This is not happening to old cars. They are going to be around for some time.
I am dubious as to whether they will ever accept responsibility but we have to try.
Sorry just read this back to myself and realised that the statement "this is not happening to old cars" is ambiguous. I mean the cars the brakes fail on are not old. Mine was less than 2 years old
Very similar to my experience here in the US: Nissan Leaf 2016 almost 2 years old, approaching an intersection with red light at about 30-35 mph and when I hit the breaks clanking noise and pedal goes all the way to the bottom and I lost all break capabilities, I pumped the break but nothing, glad I had enough time to think about hand break that brought me to stop on the side of the road. I took to the dealer and they say they could not replicate and they cant do anything. Since I am a software engineer who knows some about cars I highly suspect this is a DEADLY software bug and sadly enough Nissan is playing with fire and risking high liabilities by not addressing this from the core. I have read various posts and I suspect this is due to different wear and tear in tires that may lead to confusing ABS computer resulting on a disengaged pedal for a few seconds or until the car is restarted.

It is frustrating these guys will pay no attention to such overwhelming evidence.

I do have pictures and videos of the issue if someone is interested.

Nissan is for sure NOT! tired of speaking with them and threatening legal action: the last employee basically said bring it on!

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This is Very interesting Ive had the same thing with mine its a 2014 model this has both occurred first drive in the morning I pump the brakes as I go down the hill before the junction but still seem kinda spongy & when warm at low speed. Nissan said they could not find anything wrong!. But the Biggest & scariest 1 was when the brakes failed completely. I'd just driven about 50 miles at various speeds to my folks i slowed down to pull into there drive all was ok. Then as I turned & drove in I noticed ALL the dash lights were on.As I put the brakes on the foot pedal was solid would not move I raised my foot to actually hit the hand brake & missed, But did stamp on the the foot brake again it was soiled then it gave way & I stopped unfortunately I caught a wall but that was all just scuffed & dented the wing. Told Nissan they said bring it in so we can look at it in a weeks time! They found several fault codes never seen before apparently!! So left the car with them as they had to send info off to Nissan & cos of time differance would be about 10 hours before reply. Anyway got it sorted in the end I was going away so told them to hang onto it as was driving 200 mile & didn't trust the car not to do it again. Said about the damage & they said it was ok It wouldn't affect anything as leased Never did find out what was wrong & as far as I know lease company paid the repair. But was wondering If It did go to the Insurance company fror repair who is responsible for the damage me or Nissan? Also had problems with dash & it all lighting up like an Xmas tree while still driving told them & showed them Picture didn't no why!!
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Flip the Fleet in New Zealand has just published some recent findings on reported failures of the brake control units in Nissan Leafs and this thread has been referenced as an example of overseas experience. It relates to cars manufactured between November 2012 and February 2016.

In summary, in addition to reported failures overseas, there have been 5 reported in NZ. The typical symptoms are a feeling of no brakes with more pedal travel but reduced braking is available with more force applied.

For more details please read through the blog post at Reported failures of the e-ACT Electrically-driven Intelligent Brake Control Unit in Nissan Leafs manufactured between November 2012 and February 2016 - FlipTheFleet . Feedback via the comments section on the blog page and experiences recorded via Nissan Leaf brake system failure logbook - FlipTheFleet are welcomed.
This issue has just happened to my wife's Leaf (2016 30kwh) she was coming off the motorway onto the slip road when the pedal went to the floor during braking, luckily she didn't have an accident.
I have done a LeafSpy check and the faults shown are: C1145 ABS yaw rate sensor and C1A70 Brake control system.

Its at the Nissan Dealer now and I've reported it to the DVSA.
I know of another Leaf owner I work with and he lost his brakes in the same manner and that was diagnosed as a faulty 12volt battery.

I note what DonaldNZ has flagged up and it seems very relevant to these issues that the Leaf braking system seems to be suffering from.
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Its at the Nissan Dealer now and I've reported it to the DVSA
Scary! Is that just a typo for DVLA? If not, what organisation is that?
DVSA. Driver and Vehicle Standards Agency.
See link for safety defect reporting.

Vehicle recalls and faults
oh my word. unless there is a certain fix, there is no way I'm buying a leaf for my kids. yikes.
Quite a few people have already reported this to the DVSA in the UK (including myself) but they have not been able to do anything about the issue. I guess the only time something will be done will be if someone gets killed (God forbid that this happens). Nissan UK are not interested about this (several people have had senior members of the Nissan technical team look into their cars) as they have concluded that there is no fault (clearly there is). However, seeing that we have reports from the US and further afield would seem to indicate that this is indeed a global issue unique to first generation cars.

Certainly with the new LEAF, this issue is not apparent (due to the e-Pedal function) and even without e-Pedal enabled, the braking function is far better than the first generation LEAFs.
The DVSA have instructed the dealer not to repair the car until they have inspected it, Nissan UK tech is going to inspect as well, may be at the same time.

When you look on line there has been plenty of accidents already, there will be a serious accident if this isn't sorted properly .
I looked into this to see if I could isolate it to earlier model years but posts continue thru the newer model years. Such a shame, such a great car. I'd even consider it if Nissan stood behind it but these stories of owners replicating the problem in the dealership lot on camera in front of Nissan personnel cause me to consider other EV brands.
@anemic I wasn’t aware of the stories you mentioned do you have any links please? Brakes on our LEAF have been ok but they’ve never inspired confidence so would be good to know if I can simulate the failure conditions to test my own car...
I have had quite a few Leaf now.
Two at a time mostly.
Only thing I found was that when you went over grids or sketchy surfaces in the wet it felt like it just gave up braking but would soon grab again. Never had that at all in my 40.
Not great but I think completely different to the failings described here.
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2017 car and I've experienced something similar a couple of times. Under braking hitting a bump then the deceleraton from braking is reduced significantly feeling like you've hit black ice. Unsure what is lost regen or brakes but there is still some deceleration so you do still stop but is still a squeaky bum moment as it's not as soon as you expect. Didn't feel any pulsing from ABS as some have, it's just the sudden loss of deceleration that is disconcerting and potentially dangerous.
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I just wanted to add some experience from the world of VW. It's related to braking though the failure is different. My Golf GTE has an electric power booster for the braking system as it can run entirely on electric power for about 25 miles. There is no engine boost or manifold vacuum system, and the booster operates entirely from the 12V power supply.

Several months ago, the fuse on my 12V battery failed in an intermittent manner. This meant the car would start when jumpstarted, or intermittently if the fuse was in the right position. The car presented a simple warning message, "12V battery fault. Vehicle may not restart. Visit workshop." I interpreted this as the car stating that there was an urgent fix required, but that the car was still driveable provided that the car was running (at least in my case, as all I wanted to do was drive it to the garage to have the battery replaced; I hitched a lift with a friend into work for the other days.)

While driving in the 3rd lane on the A58 in Leeds, a 40 mph dual carriageway, I experienced a total loss of 12V power. Immediately, the brake pedal shot up and kicked me in the foot (which hurt), and it became very stiff to press. However, the brakes did still work with a large amount of force, possibly helped by my relatively low speed (25-30 mph). I was able to guide the vehicle to the side of the road to the ire of most other road users (no indicators, sorry) at which point I was stuck holding the brake pedal as the car would roll if the pedal was released. With no electric power, I had no parking brake. I eventually realised I could leave the car in "P" (mechanical gear lever), though I was quite reluctant to do this as I couldn't be sure of the mechanical strength of the parking pawl on a hill, I had little choice. Once in "P" the car would not leave "P" - it seems like there's a mechanical interlock of some kind that requires power to release.

The police attended the scene (I didn't call them, they were just passing by) and luckily they were able to obtain a jump starter from a nearby Harley Davidson garage. Once jump started the car came sufficiently to life to allow it to be rolled into the bus stop nearby and the tow truck was then able to take it to the garage to have the battery replaced. Ironically, I was driving the vehicle to this same garage to have the battery/fuse combination replaced. After this the car functioned just fine and it is apparently a common fault on the GTIs and GTDs too.

A few months later, I did a technical analysis using a VCDS adapter to monitor the 12V power supply voltage, after the car had been fixed. I found that after about 15 minutes of driving, the car would briefly power off the DC-DC converter for about 10 seconds at a time. The net result is that if there is a 12V battery fault, then there is nothing to "catch" this power supply, and so you lose everything, immediately, with no warning! I could only dread to think what could happen if this had occurred at higher speeds. The non-assisted brakes may not have been sufficient to stop in time.

Now, I understand that cars may experience technical faults, but I would like to know why VW decided to build a car where if there was a 12V fault, it decided to switch off the DC-DC converter for brief periods of time. Why not just leave it switched on all the time in the fault state? The big issue here is how the car lures you into a false sense of security - it runs for at least 15 minutes and then decides to start cycling the power to the 12V battery for reasons unknown to me. And then, if there is a power failure, why all power assistance is immediately lost? In all my ICE cars, vacuum-boost is still available for a few pumps after the engine is switched off, which is usually enough to come safely to a stop in case of an emergency. It seems like a defect to me for this function to be immediately unavailable.
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@tom66 Wow, thanks for sharing. I am also considering the e.golf despite owning 14 vw/audi ICE cars. I have not heard of this story with the e.golf but it's worth a google!

@Hz0j3m I just googled leaf brake failure and was treated to lots of similar horror stories

Thank you Leaf Drivers, for sharing your inputs as well. I really want to own that car but I have such a hesitation due to the brake failure stories.
@anemic I think it is easy to be afraid of problems like this. In my case all I would argue is that a 12V battery fault should be a critical fault. In other words the car should not let you drive at all if there is a risk of a 12V failure. The GTE is a fantastic car otherwise, and is the best car I've ever owned.

The issue with the Leaf is different and hopefully it is not as common, however I would again suggest that it is unlikely to be common. If there is a serious fault present then a recall is likely.
@tom66 Wow, thanks for sharing. I am also considering the e.golf despite owning 14 vw/audi ICE cars. I have not heard of this story with the e.golf but it's worth a google!

@Hz0j3m I just googled leaf brake failure and was treated to lots of similar horror stories

Thank you Leaf Drivers, for sharing your inputs as well. I really want to own that car but I have such a hesitation due to the brake failure stories.
It's something I'll bring up at the next service but isn't stopping me driving the car.
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It seems to affect only Generation 1 Leafs. Reported failures of the e-ACT Electrically-driven Intelligent Brake Control Unit in Nissan Leafs manufactured between November 2012 and February 2016 - FlipTheFleet

Gen 2 ‘40kWh’ models now in production appear to be running fundamentally different classes of brake control unit firmware, and we have not been able to find any reported failures in these Nissan Leafs.
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