Lost braking 3 times in the past 5 months on my 2015 Leaf!

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ctesti

Member
Joined
Jan 21, 2022
Messages
9
Location
Mountain View, CA
I lost braking 3 times in 5 months on my 2015 Nissan Leaf, the first 2 times Nissan blamed it on a faulty 12v battery. They replaced the battery twice, and the problem came back again this morning. I finally got LeafSpy and found out that I'm having the following errors:

U1000 0108 ABS CAN Comm Circuit
U110D 0108 E-Driven Intelligent Brake Comm BRC-130
P3195 0008 EV/HEV CAN Error EVC-272
U1000 0008 EV/HEV CAN Comm Circuit


Now after a few hours braking came back, but the red/orange warning lights are on, and the error codes are still there. Same thing happened in July and 2 weeks ago: by the time the car was towed to Nissan, the brake "magically" came back without doing nothing!

Nissan tried to explain to me I was "not driving enough" to keep the 12v battery fully charged, which would explain randomly having the brake module failing.

This time the battery was replaced again last week, I'm reading 12.7v with the Leaf stopped, so I can't take the battery excuse anymore. Must be something else.

It's very frustrating, and dangerous, my wife is the primary driver on the car and almost got into an accident the first time. The second time I was driving and used emergency braking. Today I realized that if I put excessive pressure on the brake pedal, I do get some braking but there is a rattling sound and both red/orange warning lights are on.

I know that changing the battery a 3rd time, or just disconnecting it for 15 minutes will clear the error codes, and brakes will work fine for who knows how long. But again, this is extremely dangerous. I see many other Leaf drivers having the same issue and I don't understand why Nissan is not putting more effort in trying to solve that issue.
 
This time the battery was replaced again last week, I'm reading 12.7v with the Leaf stopped, so I can't take the battery excuse anymore. Must be something else.

Was the car turned Off, or just stopped? As long as it's in Ready mode, the DC-DC converter will mask a low 12 volt battery.
 
LeftieBiker said:
This time the battery was replaced again last week, I'm reading 12.7v with the Leaf stopped, so I can't take the battery excuse anymore. Must be something else.

Was the car turned Off, or just stopped? As long as it's in Ready mode, the DC-DC converter will mask a low 12 volt battery.

The car was off when I read 12.7v. That battery was installed by Nissan last week.
 
ctesti said:
LeftieBiker said:
This time the battery was replaced again last week, I'm reading 12.7v with the Leaf stopped, so I can't take the battery excuse anymore. Must be something else.

Was the car turned Off, or just stopped? As long as it's in Ready mode, the DC-DC converter will mask a low 12 volt battery.

The car was off when I read 12.7v. That battery was installed by Nissan last week.

I did read that. I was just making sure that you knew the procedure for checking rest voltage.
 
Your description sounds similar to what happened to my '13 during the last cold spell. In my case, I believe it was a frozen brake booster which apparently there was a recall but when I took it in a couple of days after the incident they said it didn't affect my VIN :(
From what I've read the recall is simply software and they program the vehicle to periodically activate the brake booster when off, to prevent it from freezing or sticking. In my case my Leafs sit outside which means in sub-zero temps, everything gets sub-zero and could probably freeze up. When I asked the tech if he could do the reprogram update, even if it didn't show my VIN he said he could not, which again kind of bummed me out as I'm quite sure from the description that's exactly what happened to my Leaf, whether it was supposed to affect my VIN or not!

I'm assuming from your location you aren't experiencing sub-zero temps but I wonder if it still couldn't be something with your brake booster? The symptoms I had were it felt like I had no brakes, they seemed to go way past what would normally stop the car, very scary indeed and unlike air in the brake lines, pumping the brakes didn't really seem to help, in my case each time I pushed on the brakes it went close to the floor. When it happened I was only a couple miles away from home and drove using only side streets home and really tried to plan my stops for lights and signs. When I got closer to home and bolder I tried pushing harder on the brakes and I believe they worked ok, just took a very long push, which seemed scary but again I think they would have stopped the vehicle in an emergency stop. When the brakes were acting up all the lights were on the dash and no amount of restarts at the time cleared them. When I got home I put the Leaf in a garage and heated it up above freezing for the night and the next morning it started fine and the brakes have been working fine, ever since........still has me worried when it gets really cold again, whether the brakes will be normal or go almost all the way to the floor :shock:
Oh in my case I tried hooking up a jump starter to my 12v battery and it did nothing different, 12v battery problems were my first thought but I don't believe there was anything wrong with the 12v battery.
 
Interesting, thanks for sharing.

I'm not sure though why the malfunction would not occur right from the start of the drive rather than later on.
 
Those DT Codes are from 3 different systems, but the common element is a disruption of the CAN buss communication. One common culprit is a weak or low 12V power supply.

Even a new 12V starter battery may need to be fully charged before put into service, especially for a laef which does not keep it fully charged. An open circuit voltage measurement is only one small part of testing a battery; the voltage under load is much more important for judging health.

The chemical reaction inside a battery is dependent upon temperature and is greatly affected by cold temps. A lead-acid 12V battery must be kept fully charged all the time or it will suffer permanent sulfation damage.

The "intelligent" brake booster module is an electric motor driven ball screw actuator that provides assist to push the piston in the hydraulic master cylinder--and it is powered by the 12V battery system. The brakes will still work without the 12V assist, but the stroke will be much longer.

Let's look at the story and guess the culprit:
1. Lots of CAN DTCs
2. Cold weather
3. Excess brake pedal stroke

Common cause culprit: weak 12V supply

Put an external trickle charger on it and keep it full. i like the Yuasa 1A smart charger, but whichever you can find and have confidence is all that matters.
 
nlspace said:
Those DT Codes are from 3 different systems, but the common element is a disruption of the CAN buss communication. One common culprit is a weak or low 12V power supply.

Even a new 12V starter battery may need to be fully charged before put into service, especially for a laef which does not keep it fully charged. An open circuit voltage measurement is only one small part of testing a battery; the voltage under load is much more important for judging health.

The chemical reaction inside a battery is dependent upon temperature and is greatly affected by cold temps. A lead-acid 12V battery must be kept fully charged all the time or it will suffer permanent sulfation damage.

The "intelligent" brake booster module is an electric motor driven ball screw actuator that provides assist to push the piston in the hydraulic master cylinder--and it is powered by the 12V battery system. The brakes will still work without the 12V assist, but the stroke will be much longer.

Let's look at the story and guess the culprit:
1. Lots of CAN DTCs
2. Cold weather
3. Excess brake pedal stroke

Common cause culprit: weak 12V supply

Put an external trickle charger on it and keep it full. i like the Yuasa 1A smart charger, but whichever you can find and have confidence is all that matters.

Thanks for the explanation. I can see that cold weather or a bad battery could be the culprit. However I do live in a warm climate, so cold is not an issue in my case, and I already trickle charge the battery once a week, even though it's very inconvenient... The dealer conditioned and installed that battery last week. They did the same thing 5 months ago during summer time.

This time I monitored the battery charge: 12.70v when the car is off, for past week.

So I have a hard time to accept that 2 brand new batteries, fully charged, could still be the reason why I lost braking while driving on a warm day.

How could a car braking system be designed in a way that the smallest variation in 12v battery charge would have a catastrophic failure of the brakes with zero warning? There are dozens and dozens of reports of the same failure all over the net, I'm just surprised that no recall has been issued yet. Are they waiting for fatal accident to happen? Do they really expect all the leaf drivers to trickle charge their 12v battery every single night? :shock:

That does not make any sense to me.
 
SageBrush said:
Interesting, thanks for sharing.

I'm not sure though why the malfunction would not occur right from the start of the drive rather than later on.
Good point, in my case it was right from the get-go although the funny thing is I had driven the Leaf for lunch and it was just fine, it only acted up when I restarted the Leaf and went to back up. I almost backed into someone as I wasn't expecting the pedal to travel so far, I was totally caught off guard.
Anyway, it sounds like the OP is in a much warmer area and if indeed it happened once driving, shouldn't the 12v battery be charged from the DC to DC charger?
I suppose one thing that would help eliminate a low 12v battery would be a simple voltmeter that plugs into the cigarette lighter so they could see the state of charge with just a glance. Here's a link to the one I have but unfortunately in my case was in my other Leaf, it also has a USB charging port so it does double duty and for only $13.
https://www.amazon.com/Jebsens-Charger-Battery-Monitor-Voltage/dp/B01N00I4TM/ref=dp_prsubs_1?pd_rd_i=B01N00I4TM&th=1
 
Given the above, it's unlikely to be the 12 volt battery. When that happens while driving, it can mean a very dead 12 volt battery that is acting as a giant resistor, but that seems unlikely here. And the voltage has to be really low, like below 12.0 volts. Small variations in voltage within the normal range (12.2 to 12.9 or so) don't cause that.
 
ctesti said:
...
...
How could a car braking system be designed in a way that the smallest variation in 12v battery charge would have a catastrophic failure of the brakes with zero warning? There are dozens and dozens of reports of the same failure all over the net, I'm just surprised that no recall has been issued yet. Are they waiting for fatal accident to happen? Do they really expect all the leaf drivers to trickle charge their 12v battery every single night? :shock:

That does not make any sense to me.

It's possible that the paradox could still be explained by a weak battery that is not revealing itself on a voltmeter check.

Resting voltage is not conclusive proof of a healthy battery. A load test is more definitive. I had similar problems crop up when one of my batteries developed a problem. Resting voltage was nominal, but I had repeated episodes where the dash would light up like a christmas tree. I finally put a load on the battery and the voltage dropped like a rock, which caused no end of trouble for the LEAF systems during power-up, including sketchy braking behaviors. All was fixed by a new, healthy battery and clearing the many DTCs.

This doesn't mean that your trouble is the 12V battery but I'd say it's worthwhile to get the 12V load-tested. Some parts stores will do this for free, or you can purchase a load-tester fairly cheaply. I now consider it good practice to load-test a lead-acid battery periodically to keep tabs on its health.
 
Nubo said:
I now consider it good practice to load-test a lead-acid battery periodically to keep tabs on its health.
I think this is good advice. The last time I played around with this, I thought I would add a somewhat known load to the 12v for an hour or so and then check the 12v voltage. The obvious choice was the headlights, but the car would turn them off when the DC-DC converter was open.

Is there a way to do this ? I think I am asking how to enter ACC mode. I thought it was POWER button without holding down the brake pedal but my recollection is that did not work as intended, meaning the lights turned off after a few short minutes.

^^ This is all from memory, so I might be way off-base.
 
SageBrush said:
Nubo said:
I now consider it good practice to load-test a lead-acid battery periodically to keep tabs on its health.
I think this is good advice. The last time I played around with this, I thought I would add a somewhat known load to the 12v for an hour or so and then check the 12v voltage. The obvious choice was the headlights, but the car would turn them off when the DC-DC converter was open.

Is there a way to do this ? I think I am asking how to enter ACC mode. I thought it was POWER button without holding down the brake pedal but my recollection is that did not work as intended, meaning the lights turned off after a few short minutes.

^^ This is all from memory, so I might be way off-base.
It's changed between the Gen 1 and Gen 2. In the Gen 1, ACC mode would run for 15 (30?) minutes and shutdown automatically. ACC + On Mode (not sure what to call it, you press the power button twice while NOT holding the brake pedal to enter this mode) works differently now. On the Gen 1 Models, this *second* mode would run forever and if the 12V battery voltage got low enough, it would switch on the DC to DC converter from the main battery pack and then power everything (or charge the 12V also) until you shut it off. On the Gen 2, this *second* mode also shuts off after 15 minutes automatically (if not plugged in and charging).
The Gen 1 can kill the 12V battery in ACC mode, I've tested it myself. :lol:
In the ACC + On mode, the Gen 1 will try to charge the 12V battery once it reaches 10.5 V by switching on the main battery with the DC to DC converter. If the battery is too depleted to do this at 10.5V, the whole thing dies, again tested this one myself. :lol:
The Gen 2, using ACC + On mode, if the battery voltage gets down to 10.5 volts, it just shuts off like you powered it off. Either that or the battery died but did not cause a DTC code, I'm not really sure about that on my Gen 2s yet... :?
 
I'm not 100% convinced this is a 12v battery problem...but if it is, I have an excellent solution for monitoring your 12v battery: the Anti-Gravity Battery Tracker (https://antigravitybatteries.com/products/accessories/battery/chargers/bluetooth-tracker-lead-acid/). I used one of these (albeit the Lithium version) before I installed my OVMS module (which also tracks 12v battery behavior). The Battery Tracker also has some diagnostic modes that may be helpful...and it's not all that expensive.
 
Stanton said:
I'm not 100% convinced this is a 12v battery problem...but if it is, I have an excellent solution for monitoring your 12v battery: the Anti-Gravity Battery Tracker (https://antigravitybatteries.com/products/accessories/battery/chargers/bluetooth-tracker-lead-acid/). I used one of these (albeit the Lithium version) before I installed my OVMS module (which also tracks 12v battery behavior). The Battery Tracker also has some diagnostic modes that may be helpful...and it's not all that expensive.

Thanks for sharing! Nice battery monitor.

I don't buy the battery problem: the battery was replaced twice in 5 months by the dealer, and the last one is only 5 days old and shows full charge. I would think the dealer would have done proper testing of the batteries before installing knowing that the problem they diagnosed was a battery issue!

Also the fact that the problem "heals" itself without doing anything would go against the battery theory. Every single time I had the problem, the orange and red light disappeared and braking came back by the time the car was towed to Nissan.

Same thing happened 2 days ago: no braking, battery 12.70v, everything else working fine, yellow and red warning sign on. 3 hours latter on the driveway no more warning lights and brakes woking as usual. Today the car was driving like nothing ever happened. DTCs still showing through.

Because the problem is happening more and more frequently, to me that would suggest another component is failing. I just wish it would be a total failure and be done with it.
 
The error codes listed in the original post are all related to CAN bus errors. A low 12V battery can cause CAN bus communication errors, but I doubt that the 12V battery is the issue in this case since 2 replacements have been tried. Intermittent failures of control modules can also cause CAN bus errors. My 2015 had intermittent failures similar to what has been described here. The hydraulic brakes would always work without power assist, but the pedal would go almost to the floor and be very firm so it could feel like the pedal was going to the floor. Also, the ABS and/or intelligent brake controller would make incredible noise when the brake pedal was pressed.

I was always able to clear error codes and restore normal operation (often required disconnecting/reconnecting the 12V battery once or twice in addition to using Leaf Spy to clear the codes). The intermittent issue happened more frequently as mileage and time increased. Since I had an extended warranty, I eventually took it to the dealer when it happened at a time that was convenient to take it in. The dealer diagnosis was a bad intelligent brake controller. The replacement cost was about $3000 for parts and labor. I would have continued to clear codes and drive the car without replacing the controller if it was not covered by extended warranty.
 
GerryAZ said:
The error codes listed in the original post are all related to CAN bus errors. A low 12V battery can cause CAN bus communication errors, but I doubt that the 12V battery is the issue in this case since 2 replacements have been tried. Intermittent failures of control modules can also cause CAN bus errors. My 2015 had intermittent failures similar to what has been described here. The hydraulic brakes would always work without power assist, but the pedal would go almost to the floor and be very firm so it could feel like the pedal was going to the floor. Also, the ABS and/or intelligent brake controller would make incredible noise when the brake pedal was pressed.

I was always able to clear error codes and restore normal operation (often required disconnecting/reconnecting the 12V battery once or twice in addition to using Leaf Spy to clear the codes). The intermittent issue happened more frequently as mileage and time increased. Since I had an extended warranty, I eventually took it to the dealer when it happened at a time that was convenient to take it in. The dealer diagnosis was a bad intelligent brake controller. The replacement cost was about $3000 for parts and labor. I would have continued to clear codes and drive the car without replacing the controller if it was not covered by extended warranty.

Wow, thank you so much Gerry! That's exactly what's happening to me.
I also have an extended warranty, and the car is now at the dealer. They asked some help from Nissan engineers to diagnose the DTCs, I bet I have a similar faulty intelligent brake controller. I should have an update from them tomorrow...
 
GerryAZ: Ouch! Hopefully you'd filed a safety complaint w/NHTSA at www.safercar.gov. Might help others to do so, if you haven't already.

ctesti: Might help to do the same if that ends up being the fix for you too.
 
cwerdna said:
GerryAZ: Ouch! Hopefully you'd filed a safety complaint w/NHTSA at www.safercar.gov. Might help others to do so, if you haven't already.

ctesti: Might help to do the same if that ends up being the fix for you too.
The brakes still worked (without power assist) so I saw no reason to file a safety complaint. I posted this issue in several other threads over the years that mention loss of brakes. Again, I always had braking capability although the pedal effort was high when the CAN bus communication failed.
 
GerryAZ said:
cwerdna said:
GerryAZ: Ouch! Hopefully you'd filed a safety complaint w/NHTSA at www.safercar.gov. Might help others to do so, if you haven't already.

ctesti: Might help to do the same if that ends up being the fix for you too.
The brakes still worked (without power assist) so I saw no reason to file a safety complaint. I posted this issue in several other threads over the years that mention loss of brakes. Again, I always had braking capability although the pedal effort was high when the CAN bus communication failed.

I filed a complaint with NHTSA each time I had the car towed to the dealer. The first time my wife lost brake assist, she panicked and had to call 911 since it was on a busy street. When the problem happened while I was driving, I also thought I lost all braking. It's only after reading some posts here in the forum that I realized I could press extremely hard on the pedal, ignore all the weird sounds and red orange light warning and eventually get the car to brake.

However I agree with cwerdna, for most drivers they'll believe they lost all braking, that's what my wife and I thought. This could end up with a deadly accident if it happens on a highway or busy street at a red light for instance.

So I agree that filing a NHTSA could be very helpful, potentially even safe lives. These intelligent brake control modules might have a factory defect and they might start going bad after 5 or so years...
 
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