Nissan Leaf 2017 intermittent footbrake fault nightmare!

nothingsimple345

Bought 2017 Nissan Leaf EV Dec 2020. All well with the car until Feb. 2021. Due to Covid restrictions our mileage is low and more start/stop around local area, just the type of driving this EV car should be best at. 
 Feb 2021 Intermittent foot brake issue. Brakes would not operate as normal. Having to put foot down hard on brake pedal to even have some response from brakes. The next time the brakes would react normally, meaning we never knew what to expect when pressing brakes. This meant we could not drive this car with confidence that it would stop as required. Car sent back to Nissan dealer, and to their credit, this time, having experienced the fault themselves, and if they carried out everything on there report this included replacing master brake servo. (They did not examine the servo unit to prove it was faulty).  Simply stating on report all is ok. Received car back after nearly 4 weeks in garage, (waiting on parts), some weeks after receiving the car we began to feel confident in the car handling.
May 2021 the intermittent breaking fault started again, no warning lights, and as before, we returned the car quicker to dealer this time. The garage came back very quickly, same day as the car was booked into workshop, stating they could not find a fault with brakes. We insisted on further checks, after all we are talking of faulty brakes. Dealership have not been cooperative this time insisting we take the car back as no fault can be found. We have lodged a formal complaint using Consumer right's act 2015,car brakes faulty, against dealer. Nissan dealer have now sent car back to us (without agreement) and with a report indicating tests carried out. With a strange last section from Nissan technical department stating "ensure customer has not left anything plugged into OBD port, usb port 12v socket, snooper or any front dash camera". Are they inferring that if something is plugged into OBD port (whatever an OBD port actually is) it will make the brakes faulty. We can never be comfortable in driving this car, it is scary enough driving around busy mini roundabouts in our area without worrying if the brakes will work normally. To me any report like an MOT certificate is really only valid on that date, whilst covered by law for a limited time. Whilst no general brake issues for this 2017 model are known it is not to say there is not a foot brake issue with this car. We just want an agreeable settlement as we could never trust this car, or this dealership either now given the after sales manager's attitude. They verbally said we could trade the car in for another car, but they only deal in Nissan cars.
Horrible situation, Nissan GB are not responding to e-mails, only automatic response, and if we get another complaint ref number (we have 5 different numbers now).
Having taken advice it is illegal to drive a car, or allow anyone else to drive this car knowing of a potential safety issue, we could be liable should brakes fail. Does this report from garage indicating "no fault can be found", mean they have taken the responsibility, of safety for this car? Not that this makes me feel any better.
Our first venture into owning electric vehicle has turned into a nightmare, certainly not good for anxiety levels already strained with Covid restrictions and health issues.
Relevant advice will be gratefully received and does any other owner of this type of car have/had footbrake issues with this model/year?

tacpot12

The OBD port is the connector that the garage plug their diagnostic computer into on the car to read the fault codes. There are certain accessories that can be  plugged into an OBD port, but you would know if  you had plugged anything into it. I would take the NISSAN Technical Department as indicating that any sort of electrical drain might cause the brakes to fail. This is not an encouraging point as the car should be designed so that any unexpected drain cannot cause the brakes to failure until every other system on the car has already failed. Steering and then Brakes should be the last systems to fail on any vehicle.

I doubt the dealer's report saying that no fault can be found means that they are accepting responsibility for the safety of the car.

This is a tricky issue as the Consumer Rights Act 2015 gives you a recourse if the car is faulty, but if no "fault" can be found then the dealer can't fix it. However, when you returned the car to the dealer in February, it is also possible that they could not find any fault then, but as they had experienced the failure themselves they replaced everything that might have caused the issue. I would suggest that if they did fail to find a fault the first time around, then they are trying it on in not performing further investigations. I would send a letter before action, and then sue them for a refund on basis that their first fix did not work. 

I think you will find the judge sympathetic to your point that you cannot safely drive the car you have bought nor, in good conscience, sell it to anyone else at a fair price.

AdrianC

You bought a 3yo car in December 2020.
Three months later, in Feb 2021 you had braking issues. They diagnosed it, agreed there was a problem, replaced parts, and fixed it.
Three months later, in May 2021 you had more braking issues. They can now find no further fault, and cannot reproduce the issues you say you were having.

It sounds as if they're suspecting the issue is with the brake regeneration not working - the normal footbrakes only come into play in heavy braking in an electric vehicle, with light braking putting extra load on by generating charge.

So, yes, it could very well be a computer issue. And that could very well be caused by interference from badly-designed things plugged in. If those things aren't plugged in when the car is in the dealership, they cannot find out if that's what's causing the issue.

If they're test-driving the car and finding no fault... What do you want them to do?

(as for the "servo", does it even have one? I'd be very surprised. There's no vacuum to draw on...)

facade

There is a servo, it is an overcomplicated electrically driven one.

The e-act system applies regenerative braking when you lift up the throttle, and when you physically brake as well, it does some calculations to decide how much fluid pressure to apply to give you the amount of deceleration it thinks you were expecting in conjunction with regenerative.

When it all goes wrong, you still have mechanical brakes, but you need both feet and a shove from the backseat passenger to apply them, especially if the motor is still trying to drive rather than working as a brake.

There is plenty on t'interweb about failures, the consensus is they are software related.

e.g.

https://www.mynissanleaf.com/viewtopic.php?p=573044

https://flipthefleet.org/2018/leaf-brakes-failures/

Have to say I was told categorically not to buy a leaf by my brother in the garage trade, as they "break all the time", seems they don't actually brake all the time.... 

AdrianC

facade said:

There is a servo, it is an overcomplicated electrically driven one.

A pump, not a servo. Unsurprised about that.

HoofeHearted

If something is left plugged into the OBD port, (or the other suggestions), will cause drain the 12v battery.

Are Nissan suggesting that low/drained 12v battery causes the brakes to not operate sufficiently!?!

Ectophile

Something left plugged into the OBD port will be connected directly to the car's control/data bus.  It could potentially cause all sorts of problems with the car's electrical systems.

nothingsimple345

Hi, thanks for comments so far. We never knew what an OBD port was until the technician's report. We have certainly not plugged anything into this port, and a bit confused at the wording on the report as they refer also to USB and 12v socket. As is commented if we did have something plugged into the USB port and/or the 12 v battery, surely this should never have an impact on the braking system. Whilst we were quite reassured after the first time the car went into the garage, that the testing and the replacement of brake servo meant we had some confidence all would be well. And all was well, and just as this brake fault was receding into the back of our minds up pop's the fault again. Like the advert for weed killer, it pop's up and says "hello", then disappears for a few miles then pop's up again. If this was a front electric window intermittently not going up and down it would be acceptable, but these are brakes not functioning as required when we requiring them to work. Whilst I recognise that the technical department pulled out all the stops to correct this fault the first time. (Cannot understand why they did not disassemble the brake servo to prove it was faulty). They assumed all was well on there test runs, and as said above we were getting confident as well. Intermittent faults are the worst kind of fault, and until it becomes a permanent fault can be difficult to trace. In my working life I was a toolmaker, moving into high volume production and know full well the frustration of intermittent faults
These are brakes, which should be failproof and are rightly monitored by yearly MOT. Yet even an MOT certificate is only accurate on the date and time it was tested. Like the last report from the garage they can only test what is in front of them, but as we know only to well with our anxious moments when the car brakes fail to operate there is a fault. If only we had a warning at least before we need to stop, knowing these brakes do have an intermittent fault we could prepare to do the following, as FACADE quotes " need both feet and a shove from the backseat passenger to apply them, especially if the motor is still trying to drive rather than working as a brake."
This is an exact illustration of what happens, except the next time we brake the brake can work normally, but because we are expecting the fault and push hard on the brake, stop suddenly, to the annoyance of the driver in the car behind.
There is design, mechanics, hydraulics, electrics, electronics, and to add to woe's software. All these have to work together with the driver's foot in order to control the car, and slow down and stop when required. When you look at these closely it is a wonder how we all take these for granted. A wonder we get out of our bed's in the morning. 
Nissan are only giving us automatic confirmation of our E-mails now, no communication's at all.  We now have 6 different ref numbers all relating to the same fault. No letter when the car was returned to us if the fault should occur again call the garage for support. So our not fit for purpose will remain and this car sits on our drive unused. Such a shame I really enjoyed the comfort and quietness of this car, but I do not see me getting another electric vehicle.

BOWFER

facade said:

Have to say I was told categorically not to buy a leaf by my brother in the garage trade, as they "break all the time", seems they don't actually brake all the time.... 

This is rubbish.
They regularly do very well in reliability surveys and faults are rare.
I had one for a year and am still a member of Leaf forums, as I intend to get a 62Kwh model ASAP.

BOWFER

nothingsimple345 said:

Such a shame I really enjoyed the comfort and quietness of this car, but I do not see me getting another electric vehicle.

I went to one bad Indian restaurant, therefore I'm giving up on Indian food.
Same thing, and equally daft.

daveyjp

There are a lot of a modern car systems which rely on a brake pedal switch costing a few quid.

If this suffers a problem it can throw up dozens of faults.  A friend had it with his car.  Warning signs all over the dash, stability control not functioning etc.  New switch all sorted.

My own vehicle was subject to a recall after it was found that silicon in car valeting cleaning fluids could affect the switch contacts.  This causes the brakes and abs not to work correctly, brake lights not to illuminate etc, A newly designed switch was fitted.

Have Nissan even considered this the source of the problem?

I'd certainly be fitting a dashcam to record journeys and have evidence should it happen again.