2021 Tesla Model Y Electrical System Problems

While on my way to run an errand, I opened up the back door to strap my 2 year old in, when i closed the door, the car would not open whatsoever, after trying for a few minutes with the phone key app for tesla and the physical key fob, nothing would work. I had to end up calling 911 and firefighters came out and had to physically open the door, which broke the window. The car was completely unresponsive and would not turn on. After researching what happened, it turns out the 12v battery had died. I was able to jumpstart the car with jumpers and that was able to open up the rest of the car's doors. However, during the time my son was stuck inside with the over 95 degree weather, the had no safety mechanism in place to open it physically like a traditional key fob would. It is very disheartening knowing my son could have potentially lost his life over something so simple that could be resolved with a physical keyhole on the outside like almost every traditional vehicle has. This is something that should not occur, ever. The fact that the car was able to open up once more before completely dying and perfectly at the wrong time after closing the door while my son was trapped in there in complete heat was very disappointing.

Detailed Description of the Defect: Friday Incident: While picking up my son from school, the vehicle abruptly disabled multiple safety and driver-assist features. The car rolled backward on a slight incline, failed to display any surrounding vehicles on the FSD visualization, and retained accelerator input even after I removed my foot from the pedal. The vehicle continued to speed up slightly in Drive and Reverse without my input. Soft resets did not resolve the issue. Monday Incident (Collision Caused by Malfunction): On Monday morning, the same malfunction occurred. As I reversed into my garage with the door opening, the car again held the accelerator input after I lifted my foot, causing the vehicle to continue moving backward unexpectedly. The vehicle struck my garage door, causing property damage and a dent to the trunk. This was not driver error. It was unexpected propulsion after pedal release — an extremely dangerous condition.

The driver rear left side door is unclear electrical control and broke so I cannot open the door from the outside. I have a child inside. This is an extreme safety hazard were an accident to occur.

The contact owns a 2021 Tesla Model Y. The contact stated that while the vehicle was parked, the contact observed the code BMSA079 on the computer, and messages "Vehicle Unable to Charge to Maximum Charge Level" and “Maximum Charge Level Reached - Reduced Maximum Charge Levels" were displayed. The vehicle was taken to a dealer, and it was determined that one coil in the battery was inoperative, and the dealer reduced the charge and refused to increase the battery charging level. The manufacturer was notified of the failure. The failure mileage was 155,000.

I was driving along one of the main highways in Orlando, Florida called [XXX], on Wednesday [XXX], in my Model Y Tesla. I was between the exits of [XXX], and [XXX]. I was in the middle lane. There was a software update issued the previous Sunday. The warning came on the display that the lane changing was not valid. At that point the car took over and accelerated. The brakes would not work, until I slammed on it after 3 times, and the car began to decelerate. The air conditioner went off, along with the electrical turn signals. I as able to get off at the [XXX] exit for it is a bit of a "hill" up in Florida, but knew I could coast into a lane hopefully no one would be in. I was able to at least coast into a parking lot, and bump the car into a concrete barrier, and a tree infront of the barrier. The car would not respond to park, neutral or the emergency brake. I tried re-booting the car 3 times and nothing. I had to call a tow truck to tow to the Tesla Service Center in Clermont, Florida. They could not get it in park either and had to drag the Tesla onto the flatbed. After 5 days of not responding to my text, I walked into another Tesla service center to plead my problem. Long story short, there is an unexplained anomaly that is in the CANBUS and cannot duplicate the error. More $ to have to tested for another week. They gave me a loaner to use, a Model S. After a few days driving it the loaner screen went blank and I was stranded. I had their loaner towed back to the service center. They will not 100% address the problem. They know it is in the CANBUS system, but now I definitely am scared to drive the car or get it back. How do I know if they will really tell me it is fixed? I fear if I get back in the car. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

This incident appears to relate to NHTSA ongoing investigation at Tesla's low voltage battery system failure causing door handle malfunction. (September 26, 2025) 2021 Model Y front and rear doors (all four) was locked down with a seven years old child inside the car at home garage driveway. Mom unable to open up doors from exterior. A few hours later, left driver door was able to open but other passengers door remained locked down. (October 2, 2025) Sent Model Y to Tesla service center and identified low voltage battery and vehicle controller failure. Tesla technician replaced those electrical components with service fee charged.

- Open rear passenger door and secured child in car seat. - Try to open driver side rear passenger door - which would not open. - Tried to open rear passenger door where child was in, and the door would not open. - Car was powered off and none of the doors opened. - After approximately 5 minutes, front passenger door opened, and child was removed form the car through the front door. - Requested roadside assistance with the diagnosis of 12V battery failure. - No warning that 12V battery was near end of life - Software updated the previous night.

After 4 years of ownership, the HV battery has failed. This has put the car at risk it stopped charging and without charging the car was no longer drivable. The battery was overheating the car was very hot the AC stopped working. This put the car at risk when drive the battery dropped significantly while driving. Yes we got it inspected they said that the battery is failing and needs to be replaced. I have a quote about the replacment parts. There was a message at the end that the battery was unable to charge.

On August 20th, 2025 at 2:50pm, my eight-month-old infant was trapped inside my Tesla Model Y for approximately 30 minutes due to a critical systems failure. The vehicle experienced an error with the 12V battery that rendered the doors, windows, and trunk completely inoperable, preventing any means of access or escape. My infant was flushed, diaphoretic, and crying while stuck in his car seat with an indoor temperature exceeding 104 degrees fahrenheit. Despite all attempts to override the system, the car remained locked, and the battery dead, and emergency services had to be contacted. Officers from the Santa Barbara Sheriff’s Department, California Highway Patrol, and Montecito Fire Department arrived on scene and, in order to rescue my baby, were forced to smash a window to gain entry. The police officer was advised by a Tesla representative to do so, as he confirmed there would be no way to override the system to open the doors. My baby was found screaming in a pool full of sweat and was carried to an ambulance, where the paramedic warned me of concerning vital signs and advised me to go to the Santa Barbara Cottage Hospital to have his condition assessed and treated, if necessary. I have obtained a copy of the police report (Case No. XXX) and will provide it upon request. Tesla confirmed that this problem with the 12V battery is common, nonetheless we were made to pay for a new window and a battery replacement. There were no warning signs leading up to the shutdown and not notifying us of this system failure and the risk involved is complete negligence on behalf of Tesla.

8k miles after warranty expired, I got this notification in my Tesla. BMS_u018 Maximum battery charge level reduced OK to drive - Schedule service Car won’t charge anymore, Tesla says it’s a High voltage battery issue and are charging $14,000 out of warranty. Online it says others have the same issue of it not working sometime after warranty expires. Tesla states batteries should run from 200-300k miles? Wanted to make this complaint since I don’t do anything to cause the battery to have a malfunction this early. No supercharging or charging to 100%.

On [XXX], after placing my young child in my Tesla and closing the door, the 12V battery failed suddenly and the vehicle became inaccessible. I was unable to unlock or enter the car. I did not receive any warning or alert that the 12V battery was about to fail. The vehicle was in my garage, and the window automatically cracked, which allowed me to monitor my child while I sought help. I called Tesla Roadside Assistance at 8:59 AM. During the call, the representative reassured me that help was being dispatched and at times described the service provider as “on the way” (timing details such as “within ~45 minutes” and the length of the initial call are my best estimates). After continued waiting with my child confined inside the vehicle, I contacted emergency services due to the safety risk. I called 911 at 10:03 AM. I later had the 12V battery replaced at my own expense. This incident involved a sudden electrical failure without warning that resulted in a child being trapped inside a disabled vehicle, and I am also concerned about the accuracy and effectiveness of roadside assistance dispatch communications during the incident. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

On July 5, 2025, I entered my vehicle parked in my home garage and the door latched shut. Upon putting my foot on the brake. Center screen was blank (did not power on). I attempted to press the unlock button on the door and there was no sound from the motor to open the door. The door was still locked from the inside of the vehicle and I was locked inside. I waited around 5 minutes (after attempting to call my wife to try to let me out of car and tried the open the drivers door again by pressing the exit button. The door unlatched by normally the window rolls down partially to exit. This time the window did not move and I have to force the door open by pressing my shoulder hard against the interior door panel. I hear a popping sound from inside the door and the window would not roll up. I did not drive the vehicle fearing that the car would not start and my family could be trapped inside the car. I created an appointment for Tesla service for July 7, 2025 for the door locks and the driver's window that would not roll up completely and also would roll down but return to a 70% rolled up position automatically. I did received an error warning on the late evening of July 6, 2025 that the 12 volt battery voltage was low on the main center screen of my vehicle. I took the vehicle to Tesla service on July 7, 2025 and it was determined that the 12 volt auxiliary battery that was faulty and my window was repaired and recalibrated. I never saw an alert for the 12 volt auxiliary battery low voltage prior to when I was locked inside the car.

Vehicle: 2021 Tesla Model Y VIN: [XXX] Date of Incident: [XXX] On the afternoon of Sunday [XXX], while my Tesla Model Y was parked at home and charged to approximately 80%, both my wife and I attempted to enter the vehicle to attend an important appointment. Upon approach, we found the car completely unresponsive — no power, no screen activity, and we were unable to start the vehicle or release the charging cable. Despite this, both front doors could still be manually opened. However, the frameless windows did not automatically lower as they normally would when opening and closing the doors, As a result, when we attempted to close the doors, both front door windows shattered, as the glass was unable to lower and collided with the door frame. This incident clearly resulted from a critical system failure that disabled essential safety and design functions. The vehicle was not damaged prior to this event, and there was no impact or external force involved. This malfunction rendered the vehicle inoperable and directly caused costly damage. I am requesting the following: A full investigation into the root cause of the power system failure Immediate replacement of both shattered front windows at no cost A written explanation of what caused the vehicle to become unresponsive This issue raises serious concerns about vehicle safety and reliability, especially when essential functions like glass auto-drop are disabled without any warning, leaving the glass vulnerable to breakage. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Plugged a charger cord for a Garmin watch into the center console USBC right side port. Overnight the USBC port, while connected to the cord but not to the watch or any other device, overheated and melted. It burned the cords male connection into two pieces and melted plastic into the center console. The male end of the cord is now fused into the USBC port of the car. No messages/alerts on the car. Manufacturer inspected and invoiced $970.00 for parts and labor. From forums online this is not the first instance a similar situation has occurred. Assuming paper or another flammable substance was in the console, it would have caught fire

Vehicle shut down and individual was locked in the car. Unable to release the doors. Incident occurred on June 23rd with a temp of 95 degrees and higher heat index. Individual was Stuck in the car in a parking garage with no one around to hear screams for help. Called home for assistance to come to the parking garage to help free them. Informed by online article about the Model Y 2021 model having other incidents of the same. We thought it was just a freak occurrence of our vehicle until reading about the probe. No warning indications that the auxiliary battery needed replacing that controls such functions. Tesla's Repair Notes: "The vehicle was unable to power on when parked, which was verified by the technician's inspection and the customer's report. The issue was caused by a failing 12V battery. The technician replaced the 12V battery to resolve the problem. After the replacement, all systems were checked and confirmed to be running properly"

[XXX] , my [XXX] son, was strapped in his car seat, wide-eyed and confused, as we sat trapped in our Tesla for thirty agonizing minutes. The battery had died without warning, leaving us locked inside our own garage. No power, no way to open the doors. I tried to keep [XXX] calm, singing his favorite songs, but my heart raced as I called for help. A tow truck finally arrived and jumped the car—not enough juice to start the engine, but just enough to unlock the doors. Freedom at last. Tesla’s response? No roadside service; they insisted the car be towed to their service center. Easier said than done—the tow truck couldn’t maneuver it out of the garage. Frustration mounted as I realized I’d have to miss work. Days later, I drove to the service center, where they replaced the battery. But the ordeal wasn’t over. The trim was damaged during the chaos, and now every drive is accompanied by relentless wind noise, a constant reminder of that day. [XXX] still talks about being “stuck in the car,” and I can’t help but feel let down by a system that left us stranded. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

2nd Tesla loaner is damaged by rodents Chew on Car Wires.

The heat pump stopped working twice, which requires a trip to the service center and the repair to restore function is a minimum of $3,000. The vehical has no heat at all, no defrost, no cabin heat nothing! This defect happens in the coldest parts of winter and leaves the owner stranded wherever this occurs. The first time was at 52,000 miles. It wouldn't turn on. The heat pump seized. The second time was on a trip, it blow out all the freon and stopped working in Waterloo, Iowa. I was 4 hours from home and it was -4F outside. The car had 136,000 miles. Many others have had heat pumps go out in the same situation...dead of winter. The repair is $3,000 to get heat back into the car. The heat pumpscare clearly defective or not big enough and are destroying themselves every other winter in Minnesota. This is 1. Dangerous because you can't defrost your windshield. 2. You cold freeze to death in very cold conditions. 3. A very expensive repair pn a part that should last mire than a 1 or 2 years. Home heat pumpsvlast 10- 24 years!!

The contact's client owned a 2021 Tesla Model Y. The contact stated that while his client was driving at an undisclosed speed under 60 MPH, the vehicle caught fire in an unknown location. The origin of the fire was unknown. The contact stated that his client attempted to unlock the vehicle doors, but the driver's handle did not work as intended, trapping the contact's client in the burning vehicle. The contact stated that the police and fire department arrived, but were not able to get close enough to the vehicle due to the inferno. The contact's client succumbed to the fire. The fire department extinguished the fire after approximately 40 minutes. The vehicle was destroyed but towed to a tow yard. The manufacturer was notified of the fatality. No further information was available as of yet. The failure mileage was unknown.

The software for the car was showing multiple errors in the service page saying the disk space for the car was full. As a result, the car had severe lag issues and the screen completely shut down multiple times while driving on the highway. There were no user warnings and I only knew about the service warnings after speaking with Tesla support. They said it was definitely not user created and that it needed immediate service. However, the service center claimed it was not their responsibility and wanted to charge 300-500$ to look into it.