Service Brakes Problems of Nissan Leaf - part 1

This vehicle is equipped with a feature known as "e-pedal" also known as one-pedal driving which is quite common on evs. When this mode is activated, the accelerator pedal acts as a speed command (vs. Power) and when the pedal is not depressed, the vehicle applies brakes until it comes to a standstill. Recently, the system has demonstrated a fault condition, where the vehicle control module (vcm) issues a fault warning and disengages the e-pedal mode. This appears to occur randomly after the vehicle has been at a standstill for over one minute (e. G. Waiting at a traffic signal) where the driver is using the one-pedal system vs. Continuously applying pressure to the brake pedal. The safety issue is that when the system detects a fault and disengages e-pedal, the vehicle starts to move forward, requiring the driver to take immediate action to stop unwanted motion. This can lead to a collision with a vehicle or pedestrian in front of the vehicle. The desired behavior is that when the vcm detects a fault with the e-pedal system, it should engage the park mode and prevent the vehicle from moving forward. The driver must then depress the brake pedal and affirmatively command the drive mode before moving. Just disengaging the e-pedal (brake) without prior warning of a fault is a safety hazard.

See all problems of the 2018 Nissan Leaf 🔎.

Was driving the car in a neighborhood setting only going 20 mph, abs light turned on the dashboard, traction control light or some other light regarding traction came on as well, brakes failed. Had to use parking brake to stop the vehicle.

See all problems of the 2015 Nissan Leaf 🔎.

While driving normally, yellow brake warning lights came on but I arrived home without incident. Next time I drove, the warning lights were all off, but suddenly the brakes failed almost completely. I pushed the pedal to the floor and heard a grinding/clicking sound, and barely any stopping power. I was only going 25 mph, and was able to stop after 5 seconds of high foot pressure. At the same time, red brake warning light came on. I was able to get the car home very slowly, and strangely I had adequate braking power for the remainder of the short trip (although red and yellow brake warning lights remain on). I am happy to provide the car for inspection. This was extremely dangerous to the nearby pedestrians because I could not have stopped the vehicle had one been crossing in front of me. Had this happened at highway speeds, my passenger and I would have been in great danger, as would have other vehicles.

The high-voltage battery on my 2022 Nissan Leaf is subject to recall 25v655. The recall notice states that the battery cells can develop excessive lithium deposits, which increases electrical resistance and can cause rapid battery heating during level 3 fast charging. Nissan instructs owners not to use level 3 charging at all until a “remedy” is available. The issue is that the remedy described by Nissan is not an actual repair of the battery defect. Nissan states it will install software that monitors for “state-of-charge fluctuation” and, if detected, will prevent the vehicle from restarting or recharging in order to avoid a thermal incident. This means the defect inside the battery cells is still present, and the car may disable itself if the defect begins to appear. The recall materials also state there is no warning before overheating occurs. This creates multiple safety concerns: • the underlying battery defect remains uncorrected. • the vehicle can become immobilized (unable to restart or recharge) if the software detects the condition. • loss of level 3 charging capability affects the ability to travel safely or plan charging when needed. • a battery fire risk exists during level 3 charging if the defect is not detected in time. Nissan’s documents state that the software is meant only to prevent the “progression” of a thermal incident, not to repair the defective battery. I am concerned that my vehicle contains a known hazardous defect that has not been physically repaired and that the software-only response is inadequate to ensure safety. I am filing this complaint so NHTSA is aware that the remedy being offered does not address the internal battery defect itself and may leave owners exposed to continued safety and reliability risks.

See all problems of the 2022 Nissan Leaf 🔎.

My intelligent brake unit failed. I was slowing down at a major intersection to stop. The abs system activated and the brakes did not respond appropriately. The pedal went soft. Multiple lights on the dashboard lit up. My two year old child was in the vehicle with me, and we are still recovering from this traumatic experience. I considered the car disabled and had it towed to a mechanic. I then brought it to a Nissan dealership who identified that the entire intelligent brake unit needs replacing for $5,500, which is more than half of what I paid for the vehicle.

On Monday, I was departing from the supermarket parking lot. As I was waiting at the stop sign to exit the parking lot, my 2020 Nissan Leaf sv vehicle shuttered and there was a blinking notification on the dashboard stating: tm system malfunction epedal failure suddenly my ability to stop the vehicle was compromised. I turned onto the surface street and continued to pump the brakes with no response. I turned back into the supermarket parking lot and continued to pump the brakes but there was no engagement. I slowly drove around the parking lot trying to stop with no success. I eventually had to turn on the emergency brake and then force the vehicle into park. It was a very scary scenario. I called the dealership to explain the situation and the service advisor suggested that I have the vehicle towed to the dealership for a diagnostic evaluation. After sitting in the car for 30 minutes with it turned off, I turned it back on and drove the vehicle on surface streets to the dealership with no breaking incident. The next day, the service department performed a diagnostic inspection and determined that the 12 volt battery was the cause and needed to be replaced. I was relieved that this was the issue. The technician kept the vehicle one more day to drive it and be sure it was operational. In the end, I purchased a new battery. I am writing your organization to report this incident to try to avoid any injuries or deaths in the future. This incident happened to me without any warning and could have been very dangerous if I was at a busy intersection or on the freeway. There was no warning on the dashboard about the battery or maintenance warning to see the dealer. This needs to researched with Nissan motor company. Thank you [xxx] [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2020 Nissan Leaf 🔎.

I was driving about 30mph and suddenly out of nowhere my brakes went out. They went out for about 1 second and some lights went out - then I slammed on the brakes, skidded to a halt and stopped in the. Middle of the road, nearly crashing. We took it to the garage and they ran two codes and told us to take it to the dealer. The dealer quoted us about $8,000 and said it needed to "replace electrically driven brake control unit and e-harness (engine room harness) (240123nh1d)". This makes the car dangerous to drive due to failures beyond our control or regular maintenance. This is a car failure and should be covered by a recall. It is simply not safe to drive. Looking online, this has happened to other Nissan Leafs of the same year/model as well.

Brakes problem: during rain season the moisture can get into the brake system. When backing up, the brakes feel partially seized, and make squeeze sound. The problem is more serious when pulling the parking brake during overnight parking. Somehow the sound is coming out of front brakes. The sound will diminish after break several times during normal breaking. Forward collision warning system: the system only alerts driver with deeps and lights on dashboard. It doesn’t enables the brake system to slow or stop the car.

See all problems of the 2021 Nissan Leaf 🔎.

Hello. I have a 20/20 Nissan Leaf sv plus. This morning I had a total brake failure for lack of a better term. The e-pedal system, which I always use, suddenly failed while I was driving, showing a warning on screen that said e-pedal system malfunction. . . Please use pedal to break. When I went to use the pedal to break nothing happened except for this horrible sound and feel in the pedal. It barely just finally grabbed a little bit enough to stop before I hit the car ahead of me. But it was nothing short of a total brake failure, both e-pedal and manual pedal. Extremely distressing. What I want to know is how on earth when the e-pedal fails, the normal manual brake pedal doesn't work either. One thing to note, I let it sit almost all day while I was at work, went out and tried it, and it suddenly was working. I drove around the parking lot, turned it off. . . Back on . . And then the e-pedal warning came up again. I then went and purchased a 12 volt battery, as I read in some forums that it's possibly due to that. That also did nothing. Got the same e-pedal malfunction. The main reason I'm letting your agency know, is because I would consider this a total break failure, and completely unacceptable. By sheer luck I was only going about 5 mph when it first happened, and I could still barely break in time. Any help on the federal level. . . Would be great. Thank you so much for your time.

On 3 occasions the brakes have randomly failed when traveling. In 2 cases, stopping ability was non-existent except for the use of the parking brake. In the other case, stopping was significantly decreased. 13-Jan-2025, when traveling straight on a 40mph road towards a busy intersection, when the brakes were applied to slow to the intersection they failed and a red indicator light came on. Stopping ability was significantly reduced, but not completely gone. The car was able to safely divert into a parking lot without incident. When the car was powered off then on, the error went away and the brakes functioned. There were 2 other incidents prior to this, traveling at low speeds in residential areas. Braking was completely gone and I had to use the parking brake pedal to stop the vehicle. Again, after powering the car off then on, the braking system functioned normally.

See all problems of the 2013 Nissan Leaf 🔎.

Car was descending towards kailua on the [xxx] on oahu, hi. Dash lit up with warnings and acceleration and brake pedals stopped working. Brake pedal went to the floor with erratic pulsing sensation and very little brake power. Driver drove car into jersey wall to slow and stop vehicle. Battery state was 60% and battery was replaced under warranty about 1 year ago. While waiting for tow, powered on vehicle and symptoms remained as far as I could check. Brakes had no power and had to use ebrake to keep vehicle from rolling. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I was driving my vehicle and the brakes suddenly stopped working. Upon failure, the abs warning light as well as the braking system warning lights came on. I had to use my emergency brake to stop the vehicle. I had my vehicle towed to Nissan. The Nissan dealership mechanic said it was a master cylinder brake controller malfunction. It is currently at the dealership and available for inspection. The cost to repair the brake system exceeds the value of the car. This put my safety at risk because I could not safely stop my vehicle. I was minutes away from merging onto the freeway. Had I been traveling at high speeds without any braking system, my life and others would have been at risk.

The incident occurred at a stop sign where I was waiting behind one other vehicle. The vehicle ahead of me accelerated from the stop sign to turn into traffic, but abruptly slammed on their brakes. I had began accelerating up to the stop sign and was unable to stop before impacting the car in front of me. As soon as I saw the vehicle was braking, I immediately slammed on the brake pedal. Braking did not immediately occur. My wife said she was afraid that I had slammed the gas pedal because she could hear my foot hit the brake pedal and neither of us felt any braking. The Nissan Leaf was in eco mode and epedal at the time of the incident. I believe that the transition from regenerative braking to mechanical braking delayed the stopping of my vehicle. We were lucky that this happened in a very low consequence situation, but if this happened with a pedestrian or at a higher speed where emergency braking is required, this delay in braking could be dire. In addition, this vehicle is equipped with automatic emergency braking. I have heard this feature go off before in this specific car when a car is braking faster than I am. In this case, the alarm and assisted braking did not go off, despite a car stopping within extremely close proximity.

I put the car in park as I was pulling in without turning it off to grab trash from the curb and take it to the car, but the car keep accelerating. I jumped in and slammed on the bricks but it hit the brick wall to the house. I see more recent years were recalled for "unintended acceleration" and "brake issues".

On Friday, November 1, at about 3 pm, the brakes failed pulling away from the curb in a forward direction after loading equipment into the vehicle. Really stomping the brakes as though they had a fluid problem did get them to engage. I think the problem occured again backing out of my driveway prior to Monday the 4th when I fixed the problem. Again, really slamming the brake peddle got the brake to engage. You may look at the vehicle if you wish. On Friday, I was at a large senior center party and there were many pedestrian with limited mobility near the exit. An out of control vehicle could have been very dangerous. I applied experience from internal combustion engine (ice) vehicles with brake problems and that fortunately worked, but brake fluid was not the problem and there is no clear documentation of the problem in the owner's manual. This problem is an ev problem. I can't really take the vehicle to the dealership because they have failed to perform warranty service and refused to do so in the time required by MD law. To determine the cause of the problem, I checked the brake fluid level which was normal, brake wear, which was little, checked the owners manual in detail (nothing clearly stated) and then searched the internet. By Monday the 4th, I had seem a reditt post that said a dead cell in the 12-volt battery could cause a confusion in the vehicle between the regenerative braking system and the hydrolic braking system. There had been some odd behavior at startup. The dash info would flash up with missing numbers then come on normally. And, at shutdown a few time, the lights left on buzzer would sound even though the lights were off. I checked the 12-volt battery voltage and it was low, about 10 volts consistent with a bad cell. I ordered a napa battery said to fit the vehicle, and replaced the defective battey which seems to have fixed the problem. The napa store confirmed a bad cell in the old battery. No clear warnings of the problem showed.

See all problems of the 2016 Nissan Leaf 🔎.

Driving normally when the brake light, abs light, and traction control light came on. Brakes were unresponsiveness unless brake pedal was fully depressed causing a the abs brakes to engage. This caused difficulty stopping and was required to use parking brake to slow down. Restarted vehicle several times but problem persisted. Nissan dealership stated that the intelligent braking system needed to be replaced as that is what their computer stated as all the codes indicated that the module was defective. Codes and diagnostic report attached.

I am writing to report a serious safety issue with my Nissan Leaf that needs immediate attention. On two separate occasions, the brakes have failed completely without any warning while driving. A warning light appeared, stating "t/m system malfunction warning - see dealer," but by that time, the brakes had already stopped working. The only way to stop the vehicle was by using the emergency brake, which is extremely dangerous and could easily lead to a fatal accident. The first incident occurred when I was able to quickly pull into a walmart parking lot, luckily avoiding other vehicles. The second time, the car crashed into the side of my garage and hit a tree stump in my driveway, causing damage to the rear of the car and breaking the side mirror. I was fortunate enough to engage the emergency brake before the car entered the road, but it was a terrifying experience that could have ended much worse. Fortunately, did not happen while my teenage children and their friends were driving the car. After researching this issue, I was shocked to discover that many other Nissan Leaf owners have experienced similar brake failures dating back to 2012. This is not an isolated incident, and I am deeply concerned that it continues to happen without resolution. When I brought my car to the dealership, they informed me that the issue is related to the intelligent brake unit controller, and the repairs would cost $5,000. However, my vehicle is only five years old with 62,000 miles, and I believe this defect should be addressed by Nissan, not at the owner's expense. I urge you to take immediate action to investigate this dangerous defect. There is no warning before the brakes fail, and this puts drivers and others on the road at extreme risk. Does it really take a fatal accident for Nissan to address this issue? this problem has been ongoing for years, and it’s unacceptable that it has not been resolved. I hope that you will take this matter seriously and provide a solution befo.

See all problems of the 2019 Nissan Leaf 🔎.

It has happened multiple times that if I hit a pothole while braking, the brakes stop working until reapplied.

The intelligent braking system control unit failed. The car is available for inspection, it is at the dealership for repair. I was driving downhill, towards a busy intersection and without any warning, there was no braking when I pushed the brake pedal. It was my two young children and myself in the car, we drove straight through a crosswalk (luckily empty), and towards a very busy intersection (luckily slightly uphill so we were able to stop in time). I cannot imagine what could have happened if losing our brakes would have happened any other time. We could have easily been injured or killed, as well as someone else. The problem has been confirmed by the dealer. The vehicle has been inspected by the local dealer and service center, same one the vehicle was purchased from. No warnings, messages, or other symptoms whatsoever. Afterwards, the abs warning lights did come on.

Twice now - both times on the south bound richmond bridge, the automatic emergency braking lights came on and slammed on my brakes for me, as if I was about to crash when I was going 65 mils per hour, no one in front or behind me and no traffic, accident or reason. I almost lost control of the vehicle and would have caused an accident had anyone been closer to me.

[xxx] - I was on the way to work on a clear and sunny morning. After stopping at a traffic light, vehicles started moving forward through the intersection. Traffic was building and the lady in front of me stopped very quickly. When I pressed the the brake pedal to stop behind her nothing happened. The brakes did not brake! the pedal went all the way to the floor. It didn't even try to slow down. I just rolled right into the back of her. The front end of my 2014 Nissan Leaf sustained significant damage and the rear bumper of her SUV sustained minor damage. Both of us had minor neck/back pain after. I am still recovering from spine surgery and I'm concerned about any long term issues that may be caused from this accident. We were in a very busy area of atlanta and it is amazing that no one was seriously hurt. After calling 911 and being on hold for close to 30 minutes state farm advised it was okay to swap info without an official police report. I don't want this accident to count against my accident free/good driver discount with my insurance. There were no warning lights on my dash or audible brake sounds. I have had similar problems in the past with the brakes not engaging. It has been to the dealership at least 4 times for brake related issues in the 10 years that I have had this car. The dealership and 1 independent garage have inspected my brake system, including fluid, pads and rotors. Everything is in good condition. In the past there was a correlation between the 12v battery power and the brakes not working. It has not been possible to recreate the problem on demand. I've reported this very serious safety issue to Nissan consumer affairs. They deny responsibility, but will not provide it in writing. A basic google search shows that I am not the only Leaf owner that has this problem. It is parked in my driveway and is considered unsafe to drive unless it is repaired per the dealership. I am glad that no one else in my family was injured because of this. Information redacted pursuant to the freedom of infor.

See all problems of the 2014 Nissan Leaf 🔎.

My front collision system will sporadically start flashing when there is nothing in front of me. One time a dealer was able to read a code saying that it overheated, and told me that was a known issue with no solution. It was 100f, but I have had the same issue at 35f. The dealership and corporate cannot tell me how the safety system will respond with this error, either disabling my crash prevention system or possibly automatically breaking for no reason. I have taken it to the dealership 4 times. One refused to even try to read the code as it was happening. Another read the code but refused to record it. The other times they kept the car for a total of 8 days and didn’t even look at the component. It seems like they know that this safety issue exists and have no plans to address it. They also refuse to answer my question about liability if it causes my car to automatically break and cause an accident. This has happened at speeds between 0 and 75 mph.

See all problems of the 2023 Nissan Leaf 🔎.

Drove home at 7pm mild day (65-70 degrees). Stopped the car and turned it off for an hour. Had to leave home at 8pm. Turned on the car and backed up the driveway. Tried to stop but break wasn't working. . Pressed all the way that abs started trickling. Used the hand break to stop the car. Turned off the car and turned it back on. This is when I noticed all the dashboard lights are on including break and abs and had the same break not working issue. . Pulled the car into the driveway slowly and turned it off till tomorrow morning. . Started the car tomorrow morning and everything was back to normal and driving without an issue.

The contact owned a 2022 Nissan Leaf. The contact stated that while his wife was driving at an undisclosed speed, the brake failed to work properly causing her to struck the vehicle in front of her. No warning lights were illuminated. The contact stated there was a minor scratch on the front bumper. No injuries were sustained. No police report was filed. The manufacturer was made aware of the failure and sent an engineer to the dealer to diagnose the vehicle. The vehicle was diagnosed, the contact was advised that braking did in fact occurred. The contact sold the vehicle back to the dealer. The failure mileage was 24,795.

Brakes did not engage when depressing the brake pedal. No warning lights in the dash. Car was used a few hours prior with no issues. No other warnings of the failure occurred before or during my attempt to brake, aside from the lack of braking action. Occurred at a stop sign cross traffic, I turned into oncoming traffic, cutting off the other car but avoiding a collision. I confirmed the brakes did not work at the subsequent stop light, used parking brakes to stop at the side of the road. Minimal braking action seem to be present when I fully depress the brake pedal. Brakes worked normally the next day. Dealer service center states the intelligent brake control unit needs to be replaced for $5000, which is around the current value of the vehicle.

The contact owns a 2016 Nissan Leaf. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. The brake pedal had to be pushed to the floor to activate the service brakes. The vehicle was taken to the dealer where it was diagnosed with a failed electronically driven intelligently braking unit and the electronically driven intelligently braking unit needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 93,000.

I pulled into a parking spot and to ensure I stopped when I wanted to, I braked. The car accelerated, smashing into a building. I always drive in eco mode and generally use the e-pedal which was on at the time. I’m not sure if either or a combination of those may have been a factor in what happened. The car is available for inspection upon request. I was fine, but very shaken. The car is driveable, but the front bumper is mangled and the left blinker no longer works. The headlights are functional. The charger panel releases and I can pry it open, though it no longer pops up. No airbags were deployed. The car was going slow enough, there seems to be no damage to the building. I'm concerned what could happen when we drive into our garage or, worse, if there is a car or pedestrian in front of our car and rather than braking the car accelerates. I have seen several reports of similar experiences, though no resolutions or suggestions. I can imagine this being a one-time occurrence, but I am deeply concerned it is not. I've been at a loss in who and how this can be addressed. I have called several Nissan dealers. The service people that I spoke with were not optimistic about what they could discern and, more importantly, did not seem concerned. As a result, I called my long-time car mechanic who did some initial diagnostics, but they were inconclusive. There have been no other inspections. I have reported this to Nissan USA and have opened a case/claim. I don’t recall any warnings at the time. All recalls have been updated.

Brake warning sign came off and the car won't shift out of parking brake, causing the passenger to get stranded. Upon dealer inspection, there's defective wire hardness which has been noted in Nissan service bulletin ref: ntb19-054a. Dealer confirmed that it is bulk wire harness issue and will require replacement (~$3. 2k for part and labor). I have reported to Nissan since the Leaf has 22k mileage only, but rejected by Nissan that it is a manufacturer issues. Please investigate this as I have seen many similar issues with other Leaf owners and it will be un-safe to have parking brake issue suddenly pops up, where it will brick and unable to move the vehicle. Thank you.

The contact owns a 2015 Nissan Leaf. While in the driveway of the contacts residence, the contact started the vehicle with his foot on the brake however, the vehicle rolled. The contact depressed the brake to the floor, but the vehicle continued rolling until it crashed into a rock wall. The failure occurred without warning. There was many warning lights illuminated. There was no injuries and no police report. The vehicle was taken to an independent mechanic where the vehicle was diagnosed with an electrical failure, the brake booster failed. The vehicle was not repaired due to no dealer being in the area where the contact resides. The contact referenced NHTSA campaign number: 16v119000 (service brakes) as a possible solution however, the VIN was not included in the recall. The manufacturer was notified of the failure. The failure mileage was approximately 34,000.

When applying brakes, at a point in the pedal travel the vehicle deceleration goes from too little to vastly too much. This makes the vehicle challenging to drive in traffic without colliding into the vehicle in front and not stopping so quickly as to cause the trailing vehicle to collide. The dealer has confirmed the behavior. There is a TSB to supposedly address the problem, and a receipt is attached of that TSB software update being applied. However, this has not changed the behavior. This is at least partially a software issue, since the vehicle blends physical brakes with ev regenerative braking.

See all problems of the 2011 Nissan Leaf 🔎.

I was pulling slowly into a parking spot. The vehicle accelerated all of a sudden on its own very fast. I slammed on the brakes and the vehicle did not stop. It ran us on a sidewalk and crashed into a pole. Luckily no one hurt. Progressive is calling the car a total loss, but they have done nothing the car is still at a parking lot near the crash. Nissan is also doing nothing. I feel that I deserve better treatment. I have a good driving record and my rates are going to go up. I have not been offered a replacement car. The car is very dangerous and I would never drive another Nissan.

Brake pedal goes to the floor with no braking power. Grinding sounds, then finally brakes engage, but feels like the emergency brake. Super dangeraous, happened on the freeway. Checked 12v battery, based on what I read on line, battery had and still has strong charge. Next day, brakes work just fine. No problems. Happened again on highway a few days later, again, no braking power until just at the end, cant drive the car at any speed now, battery still fine. No cold weather here (unlike the many other 2015 Leaf owners reporting the same issue. All dash warning lamps come on. Again, car drives fine the next day. Nissan denies any recall being needed, despite the hundreds of reports of similar dangerous problems.

Warning lights, abs light and brake light illuminated out of nowhere. Unable to brake. Used a lot of force to get the car to slow down. Dealership inspected and said module short circuited.

I was driving on the highway when the car in front of me applied their breaks - I took my foot off of the accelerator but the car did not slow down. I applied the breaks but they did not work - in fact, the car seemed to accelerate. I heard the collision alarm sound but the automatic emergency braking system did not engage or stop the car, so I crashed into the car in front of me. Air bag deployed and then the car filled with smoke from the batteries but I couldn't get out as the power locks didn't work or allow me to open the door. The emt's had to break the rear window to get me out of the car.

On 9/17, 2019 Nissan Leaf s 40 kwh lost braking power just after start up. I started the vehicle, placed the vehicle into drive and went to creep through open parking spot. The brake pedal was either dead or lost enough power to feel dead. The vehicle was returned to park in order to stop slow roll. No injuries or damages. Experience seems similar to NHTSA id 11488058. I don’t recall whether any warning lights came on as I rushed to power down the car. No indicator lights illuminated after restart and vehicle drove home without issue. A few hours prior to brake issue, a humming/ringing sound was heard throughout the cabin just after shutdown. My passengers also observed the sound, which stopped after powering on the vehicle and turning the fan dial. This had not happened before and only occurred once. On 09/18, the vehicle indicated “warning: service ev system no power”. Numerous warning lights were illuminated, a photo taken, and a tow truck scheduled. Two hours later, I went to check whether the vehicle could be placed into neutral. The vehicle started and went into gear without issue and no warning lights illuminated. The vehicle was towed to the dealership for inspection as precaution. My 12v battery was the original battery, so I suspected it needed replacement and asked the dealership to test it. I have read online about other issues from Nissan Leaf owners when the 12v battery is deteriorated. Dealership confirmed 12v battery failed testing. They were not able to duplicate the brake issue described above. The only time that the vehicle provided a warning about the 12v battery was when it generated the warning described above once. Otherwise, no indication that battery needed replacement. Nissan needs to provide a system update to give the driver more specific 12v battery health information. Also address the 12v battery more clearly in maintenance schedule. Vehicle operating as expected with a new 12v battery installed.