grabby brake issue - TSBs, workarounds, suggestions

[TimLee]

...So what is a "tsb" Is that a technical service bulletin? I'm getting a little concerned that it's been out of service to me for almost three weeks over the last 4 months.

Yes.
Lots of reason for concern.
From what I have read on MNL, I am not convinced Nissan has ever fixed the gabby brake problem even on the newest 2015s.
They never fixed 2011.
Most people with time have just adjusted and learned to tolerate or live with it.

But that learning makes your braking when you drive a normal braking vehicle a bit problematic.

 

[paulk]

I've got a '14 SV and have grabby brakes at low speeds when coming to a stop. It is much more noticeable when driving in ECO mode. I suspect it might be tied in with the regenerative brakes. Haven't gone dealer, just adjusted my braking to a lighter touch so far.

HERE IS THE GRABBY BRAKE TSB: NTB14-017

TELL THIS TO THE TECHNICIAN AND THEY WILL PERFORM THE UPDATE
DEALERS TYPICALLY DON'T RECOGNIZE THIS NEED UNLESS YOU POINT IT OUT AND TELL THEM.

 

[cwerdna]

I've got a '14 SV and have grabby brakes at low speeds when coming to a stop. It is much more noticeable when driving in ECO mode. I suspect it might be tied in with the regenerative brakes. Haven't gone dealer, just adjusted my braking to a lighter touch so far.

HERE IS THE GRABBY BRAKE TSB: NTB14-017

TELL THIS TO THE TECHNICIAN AND THEY WILL PERFORM THE UPDATE
DEALERS TYPICALLY DON'T RECOGNIZE THIS NEED UNLESS YOU POINT IT OUT AND TELL THEM.

Not sure that will help. The TSB only says it's for '13 Leafs before a certain VIN range and built before Nov 02, 2013. It's available under http://x.nissanhelp.com/forums/Knowledgebase.html?catid=783#.VROSIY4bKE0" onclick="window.open(this.href);return false; (for '13s).

I don't see it or an equivalent under http://x.nissanhelp.com/forums/Knowledgebase.html?catid=911#.VROSHo4bKE0" onclick="window.open(this.href);return false; (for '14s).

One would think that all Leafs built after 11/2/13 already have the updated firmware.

 

[gbarry42]

One would think that all Leafs built after 11/2/13 already have the updated firmware.

One would think that after a year and a half of this, with the first firmware update in 2012, that all following cars would have the fix and not exhibit the problem.

One would think that if the problem refused to go away, that an engineer or tech would capture logs of all the sensors in the brake system, plus some firmware break points, and drive around until they found out what the true cause was.

I can only conclude at this point, the best advice is not to think.

 

[cwerdna]

One would think that all Leafs built after 11/2/13 already have the updated firmware.

One would think that after a year and a half of this, with the first firmware update in 2012, that all following cars would have the fix and not exhibit the problem.

'13 Leaf underwent a substantial redesign, including different OBC, moved to the front, and redesigned motor (http://articles.sae.org/11993/" onclick="window.open(this.href);return false;, just found http://saegtl.org/ev/data/uploads/ev-content/gtlev_tp_2014-01-1879.pdf" onclick="window.open(this.href);return false;, ooh!). One would imagine the braking related firmware is different between pre-'13 and post-'13 Leafs.

 

[Sondy132001]

Thanks for the info here ! My brakes (2012 Leaf) are grabby now and I don't like how it stops you so suddenly !

 

[TomT]

Interestingly, the grabby brakes literally disappeared when I got my new battery... It makes me think it is at least partially related to regen (which was dramatically reduced before the new battery)...

 

[DaveEV]

Interestingly, the grabby brakes literally disappeared when I got my new battery... It makes me think it is at least partially related to regen (which was dramatically reduced before the new battery)...

People have noted a short-term resolution of the issue after disconnecting the 12V battery. This is more likely than regen since there is negligible regen at the speeds at which grabby braking occurs no matter how new your pack is.

 

[TomT]

We shall see but so far it has remained considerably improved much longer than in the occasions in the past when I had disconnected the battery... The grab problem is so perverse in nature that who knows what the real source(s) of it is and the interaction involved...

People have noted a short-term resolution of the issue after disconnecting the 12V battery. This is more likely than regen since there is negligible regen at the speeds at which grabby braking occurs no matter how new your pack is.

 

[rogersleaf]

We shall see but so far it had remained considerably improved much longer than in the occasions in the past when I had disconnected the battery... The grab problem is so perverse in nature that who knows what the real source(s) of it is and the interaction involved...

People have noted a short-term resolution of the issue after disconnecting the 12V battery. This is more likely than regen since there is negligible regen at the speeds at which grabby braking occurs no matter how new your pack is.

Based on the work done to mine a few weeks ago, propulsion, regen, and braking controls are interrelated. Grabby brakes on mine went away with replacing the brake/ABS control module and updating software (along with no further incidents of dead accelerator since this repair).

 

[TEG]

Not sure what did it, but the grabby problem has been gone for a while in my early 2011 LEAF. The brakes are working really well these days.

Related to brake pad wear?
Non OEM tires on my car now?
Brake firmware update I had done a while back?
Did the "mash the pedal to the floor for 30 seconds" procedure...

Anyways, I am glad it is gone for me. It was really annoying at low speeds before.

 

[lion]

Still experiencing the issue myself, so I mentioned it during my recent annual check up, but they couldn't duplicate it.

I'll have to take the mechanic out for a test drive (has to go back for other major issues), since it's still happening. I'm truly tired of having to say sorry to my passengers over and over.

 

[darelldd]

Why is the subject of this thread "resolved?"

Yikes. 2011 here with terrible low-speed grab. Dealer says there is a TSB and wants $150 to upload it. I hear from all over that this is nothing more than temporary. I've done the pedal mash to the floor. Fixes the problem for about five cycles, and I'm right back to where I was. Does anybody have a REAL resolution to this?

 

[TimLee]

Why is the subject of this thread "resolved?"

Yikes. 2011 here with terrible low-speed grab. Dealer says there is a TSB and wants $150 to upload it. I hear from all over that this is nothing more than temporary. I've done the pedal mash to the floor. Fixes the problem for about five cycles, and I'm right back to where I was. Does anybody have a REAL resolution to this?

I don't think 2011 design defect on grabby braking was ever "resolved".

But as my 2011 has gotten older it jumps up only occasionally to totally annoy me.

Not sure if it gets better with less and less regenerative braking (probably) or driver experience.

 

[essaunders]

My 2012 has grabby brakes. It is clearly related to regen - it happens when at the 'edge' of available regen bubbles. Plus it goes away if I brake in neutral.

I do not have P3227 applied.

I suspect Nissan will tell me to get P3227 done and that'll fix it (which it might, by reduction of regen in the cold...)


anyone else with a similar situation? perhaps with a solution?

 

[RegGuheert]

anyone else with a similar situation? perhaps with a solution?

No firmware Nissan has provided, including P3227, has solved the grabby brakes issue on our 2011. Lately they have been worst than ever. It was getting pretty difficult to drive. I tried the "press the brake pedal as hard as you can" trick recently and that helped a bit.

 

[dhanson865]

anyone else with a similar situation? perhaps with a solution?

No firmware Nissan has provided, including P3227, has solved the grabby brakes issue on our 2011. Lately they have been worst than ever. It was getting pretty difficult to drive. I tried the "press the brake pedal as hard as you can" trick recently and that helped a bit.

I keep forgetting to try that method. I live in a very humid area so I'm used to the Prius method:

drive on a flat road until about 50mph
put car in neutral
brake to about 10mph
put car back in drive and continue on

It scrapes the rust off the discs(rotor) so if rusty discs are causing the jerkiness it'll help.

If the jerkiness isn't affected by scraping the rotor then it's purely a control issue in the Leaf.

I suppose I need to get in the habit of using both methods

1. to scrape the rust off (using friction braking)
2. to adjust the leaf brake controller (using the long deep push on the brake pedal when the car is at a stop)

on 2 can I do that only in D or will it adjust in P as well?

 

[powersurge]

Hello Dhanson,

I don't know what you are suggesting to do, but messing with the transmission will not do anything to rotors.

Rotors are used only with "braking". They are de-rusted by applying brakes. Or spraying the disks and brakes with brake cleaner.

Your thing about going from drive to neutral,, and back to drive (especially with the leaf shifter) is a prescription for tragedy and devastation. It can easily be put in reverse (at 50mph) and wreck the car. again, shifting the transmission has NOTHING to do with the brakes....

 

[Moof]

Hello Dhanson,

I don't know what you are suggesting to do, but messing with the transmission will not do anything to rotors.

Rotors are used only with "braking". They are de-rusted by applying brakes. Or spraying the disks and brakes with brake cleaner.

Your thing about going from drive to neutral,, and back to drive (especially with the leaf shifter) is a prescription for tragedy and devastation. It can easily be put in reverse (at 50mph) and wreck the car. again, shifting the transmission has NOTHING to do with the brakes....

His suggestion is to disengage the motor so you don't get regen braking, nothing dangerous at all.

You can shift into reverse at any speed above something like 8 mph, it just puts the car into neutral and beeps at you. No damage. I've done it several times. Or you can hold the puck in the neutral position for a couple seconds and it goes into neutral without a beep. No gears change in reverse, it is just the electronics driving the motor in reverse.

 

[dhanson865]

Hello Dhanson,

I don't know what you are suggesting to do, but messing with the transmission will not do anything to rotors.

Rotors are used only with "braking". They are de-rusted by applying brakes. Or spraying the disks and brakes with brake cleaner.

Your thing about going from drive to neutral,, and back to drive (especially with the leaf shifter) is a prescription for tragedy and devastation. It can easily be put in reverse (at 50mph) and wreck the car. again, shifting the transmission has NOTHING to do with the brakes....

You seem to be confused on multiple points.

1. There are two types of brakes on hybrids/EVs
a. friction
b. regenerative

1a friction uses the rotors and brake pads
1b regen uses the electric motor

I'm suggesting using neutral to disengage 1b regen to force the car to use 1a friction so that your braking maneuver gives consistent force to the brake pads.

2. Prius or Leaf either way you can change from D to N at any speed. There is no danger of going into reverse at high speed because the computer doesn't allow it. I'm going to say its around 5 mph for the Leaf and 7 mph for the Prius. I'm not sure on the exact speed for the Leaf. We aren't dealing with a transmission, we are dealing with a computer and it is disabling and enabling modes under it's control. N disables regen. R isn't allowed above 5-7 mph whatever the Leaf allows.

3. Your statement about "They are de-rusted by applying brakes" is only true if the friction brakes kick in regularly and consistently. Most drivers of Hybrids and EVs don't brake enough to keep ahead of the rust because the electric motor is doing most if not all of the braking from high speeds and all the friction brakes are doing is panic response or braking at speeds too low for regen to work effectively. Regen is disabled around the same speed cutoff that the computer won't let the car go into reverse (around 5-7 mph).

http://priuschat.com/threads/rust-on-brakes.19973

You don't really want to *stomp* on the brakes, you want to do a long slow evenly-pressured but reasonably firm slowdown, preferably going downhill. Abrupt pressure changes can cause just enough uneven wear that over time, you could wind up with roughly the same process that causes moguls to build up on ski slopes -- friction applied more at one particular point can actually start digging into rotor surfaces and after a while it's a runaway process

http://priuschat.com/threads/brake-pads-appear-rusty.132457/

The need to clean the rotors will depend on a number of things:- Do you brake gently or hard, how smooth are the roads you drive on "bumpy roads cause the abs to operate forcing friction brake use" , are you in a wet climate, do you live by the sea, and are your roads salted. All of these will make an impact. Once the rust has established itself on the rotors it rapidly gets worse unless cleaned off.

I could go on and on trying to explain this to you or quoting others trying to explain it but I'd rather do something useful. I'm going to hope that there is enough here for you see the errors in your prior post.