2021 Tesla Model Y transmission problems

POWER TRAIN

The high-voltage battery failed unexpectedly shortly after the warranty expired (with only 9,000 miles past warranty). Tesla Service confirmed a main high-voltage battery defect and quoted a full battery replacement. A sudden high-voltage battery failure causes a complete loss of propulsion/power, creating a severe collision and safety hazard on public roads. There were no prior warnings until the system suddenly failed and rendered the vehicle inoperable. The vehicle is currently available for inspection. This appears to be a premature latent defect in 2021 model high-voltage battery packs.

NHTSA complaint #11755660 — an unverified report by a vehicle owner.

POWER TRAIN

The vehicle’s secondary Autopilot Processor / car computer is internally faulted and stuck in a continuous wake/shutdown loop. This causes severe standby battery drain (~20 miles of range lost per day while parked) and completely prevents all over-the-air software updates - including federally mandated safety recall remedies. On April 4, 2024, Tesla Service diagnosed the fault and linked it to the drain and inability to update. On the same visit, Tesla added two safety recalls (23V-838 Autosteer controls and 24V-051 Brake/Park/ABS indicators) to the work order. They then demanded ~$3,000 customer payment for computer replacement before the recalls could be performed. After I declined the paid repair, Tesla marked both recalls as “completed” via software update despite the same invoice stating the vehicle could not receive updates and remained on software version 2023.38.9 (which predates both remedy firmwares they claimed was installed). Tesla is effectively paywalling federally required safety recall remedies by requiring the customer to first pay for computer replacement first. Two additional recalls remain open (21V-389 seat belt fasteners and 24V-554 hood latch). The problem has been confirmed and documented multiple times by Tesla Service.

NHTSA complaint #11742219 — an unverified report by a vehicle owner.

POWER TRAIN

My heat pump and ac unit went out and Tesla wants me to pay $4000 for a faulty part that broke in less then 3 years

NHTSA complaint #11712754 — an unverified report by a vehicle owner.

POWER TRAIN

In early Nov 2025 my Tesla Model Y began intermittently showing warnings about the forward collision warning system and multiple sensors being offline. Tesla service replaced a faulty connector on Nov 3. On Nov 15, 2025, about two weeks later, the car had a sudden drivetrain failure while I was parking on a steep hill. I heard a loud bang from the front of the car and the vehicle immediately lost drive power and had to be towed. Tesla diagnosed a failed front motor inverter that blew the high-voltage pyrofuse and damaged the 12V battery; they replaced those parts. The vehicle is available for inspection and the repaired components and records are with Tesla. After that repair the car needed another visit for alignment and has continued to show worrying behavior: “VCFRONT offline/unable to contact VCFRONT” in the service menu, repeated “autopilot computer overheating” messages, intermittent loss or reduction of regenerative braking (braking feel changes unpredictably), a rear right seatbelt malfunction warning (later inspected and cleared by Tesla), and what appears to be significantly increased battery drain compared to before the inverter failure. This has now resulted in four service visits within about a month, all at Tesla service centers (no police, insurance, or independent shops involved). Tesla has confirmed the inverter/pyrofuse/12V failure and says the overheating was due to an air pocket in the cooling system, but the VCFRONT messages, inconsistent regen braking, and increased drain have not been fully resolved or clearly explained. I am concerned that a sudden loss of power, loss of regen, or failure of VCFRONT/autopilot systems could recur at speed or in traffic, creating a serious safety risk. Please note that I'm only able to view partially-complete paperwork from the latest service appointment in the Tesla app. I have requested this documentation from Tesla and will be able to provide all the service reports and communication as a follow-up.

NHTSA complaint #11704381 — an unverified report by a vehicle owner.

POWER TRAIN

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.

NHTSA complaint #11700358 — an unverified report by a vehicle owner.

POWER TRAIN

Summary of Issue: The vehicle has experienced intermittent drive disconnections without warning. This occurred multiple times on August 9–10, 2025, during trips between Palo Alto and Monterey. The vehicle is available for inspection upon request. What component or system failed or malfunctioned, and is it available for inspection? The suspected component is the drive unit (covered under Tesla’s 8-year Drive Unit & Battery warranty). The vehicle and its systems remain available for inspection by NHTSA or Tesla. How was safety put at risk? The intermittent drive disconnections can result in sudden loss of propulsion without warning while the car is in motion. If this occurs at highway speeds, it creates a serious safety risk of collision or loss of vehicle control. Has the problem been reproduced or confirmed by a dealer or service center? Tesla Service has attempted to inspect the vehicle but reported “no fault found.” Because the issue is intermittent, Tesla did not reproduce it during their inspection, though I documented it on August 9–10, 2025. Has the vehicle/component been inspected by the manufacturer or others? Yes, the Tesla Service Center inspected the vehicle 25 August 2025. However, Tesla has refused to provide a detailed record of what diagnostic steps were actually performed (log review, physical inspection, or drive unit stress testing). Were there any warning lamps, messages, or other symptoms? No warning lamps or messages appeared at the time of the failures. The vehicle resumed propulsion after several seconds, clearing the condition without leaving an active customer-facing alert. Concern: Because the failure is intermittent and leaves no persistent alerts, Tesla has returned the vehicle without resolving the problem or providing adequate documentation. This leaves a potential safety-critical drivetrain failure unaddressed. Requested Action: I request that NHTSA investigate potential drive unit intermittent disconnection failures in Tesla Model Y

NHTSA complaint #11683010 — an unverified report by a vehicle owner.

POWER TRAIN

A year ago I went on a road trip from Florida to Iowa in the winter, temperatures were freezing or below freezing. I got an alert to maintenance powertrain, after driving to Tesla they informed me the oil pump on the rear motor was falling apart. It was replaced. A year later on a second road trip to the same location also in sub freezing conditions the exact same error pops up, in service mode it says rear oil pump error

NHTSA complaint #11637075 — an unverified report by a vehicle owner.

POWER TRAIN

Steering disabled due to software update resulting in vehicle undriviable and having to be towed from driveway Tesla requiring customer to pay for hardware replacement due to software update failure costing $2,921.24 for the replacement, out of pocket. Required replacement of steering Rack (Dual Motor) Part - Steering Gear Left Hand Drive (1044832-00-A)

NHTSA complaint #11588656 — an unverified report by a vehicle owner.

POWER TRAIN

The main screen on my Tesla Model Y flickers while driving, as well as charging. I have a video of it happening, if you slow the video down it completely shuts the screen down for a millisecond and then turns back on. I have sent this video to Tesla, as well as Tesla technicians has confirmed the issue happening when they had the vehicle. I have had the vehicle into Tesla 3 separate times for service, they don't know how to fix the issue and keep telling me to wait. I have been dealing with this issue since January 2024 and am tired of waiting and putting my safety at risk. I feel that I have been more than patient with them and now I feel that they are now blowing me off. They don't feel that it is a safety concern even considering that the display screen went out while driving 70 mph, for 13 miles and I couldn't get it to turn back on. Aditionally the side cameras on the vehicle intermittently go out. There is no warnings or symptoms prior to it happening it just happens. I have 29 times documented of it happening to me. I have requested a buyback which was denied as well as a loaner from Tesla until they can fix the issue, yet they denied that as well. It seems that Tesla does not care about the safety of me and I want this issue to be investigated. I have the video of the Screen flickering reach out to me to get it since I cant post it in the place below.

NHTSA complaint #11586653 — an unverified report by a vehicle owner.

POWER TRAIN

When driving the car abruptly slows down. This also happened on the freeway. I get an error message that says “power limited” and a turtle symbol. This is the second time this issue has happened. Tesla service center has not been able to confidently diagnose this issue. They say it’s resolved and once I leave the service center and the problem comes back.

NHTSA complaint #11571568 — an unverified report by a vehicle owner.

POWER TRAIN

The power steering went out and it was virtually impossible to turn the steering wheel. It was unsafe to drive because you were not able to turn the car unless you were very strong. Safety issue-unable to turn the car without possibly colliding with another car. Tesla replaced the drive train. Another incident happened while getting into the car and driving it. An alert came up on the screen saying that the power train needed immediate service and that I could not exceed 60 mph. I was driving at the time. As I continued to drive to my destination the alert kept coming on with different speeds I could not drive at. It eventually got down to 53 mph and it physically would not drive over that speed and it was on the freeway and dangerous because the car kept slowing down. Tesla replaced the oil pump in the back battery. I have had this car for 3 years and it has been in the shop 15 times.

NHTSA complaint #11570374 — an unverified report by a vehicle owner.

POWER TRAIN

Battery is not able to charge . The message shows need services Bring the car to Tesla service center , they told us the battery need to be replaced. They did not tell us what caused the battery to die. The car has about 30000 miles on it . Daily driving to work. Don’t understand why the battery dies so fast . Does anyone report the same problem on 2021 Tesla model Y ?

NHTSA complaint #11535014 — an unverified report by a vehicle owner.

POWER TRAIN

The car started to malfunction its ability for regenerative braking (regen.) upon release of the accelerator. The car felt as if the regen feature was slipping - so instead of a constant brake and deceleration, the car could be felt moving forward as if accelerating. Then while driving on freeway at 65-70 mph, car lost its ability to brake when I pressed on the brake twice, instead of slowing it felt as if the car just continued at its current speed. Then the car cut its power and flashed an alert "Power Reduced - exiting and re-entering vehicle may restore operation" it then flashed an alert "PULL OVER IMMEDIATELY - Unable to drive". According to Tesla, they said it was the "LH body harness. Found that the harness was not creating an efficient connection" but they never directly addressed why it felt as if the car was accelerating when I pressed on the brake. Safety was critically comprised for myself and others who I could have hit in a vehicle collision since the brakes did not respond accordingly and felt as if it accelerated or continue to maintain its speed. The problem was confirmed by Tesla but they only addressed the car going into what they refer to as "limp mode". Car was inspected by Tesla and diagnosed the problem to a faulty/bad body harness that caused an improper signal. No warning lights or messages prior to the failure. Symptoms started the morning of the incident with the noted regen not fully engaged/working correctly. I did not have any feature setting which would have caused or replicated the lack of regen. I can provide the dealer invoice if needed.

NHTSA complaint #11518510 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2021 Tesla Model Y. The contact stated while at a complete stop with the brake pedal depressed, the vehicle rolled backwards. There was no warning light illuminated. The contact stated that the failure had been reoccurring intermittently while at a complete stop. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

NHTSA complaint #11496213 — an unverified report by a vehicle owner.

POWER TRAIN

The vehicle loose power all of sudden while driving disabling all power including loss of power steering, failure of lane departure avoidance, regenerative brakes, parking breaks, traction and stability controls. This has caused hazardous dangerous conditions on the road. The vehicle had to be towed to local Tesla repair/service center on 4 occasions. We have been given false reassurance with no definitive fix yet, continues to be an ongoing issues that recurs after few weeks that vehicle comes back from service center.

NHTSA complaint #11474647 — an unverified report by a vehicle owner.

POWER TRAIN

Steering wheel locked up and would not let driver navigate off-ramp from freeway. Car attempted to force driver to merge into a stopped lane. Auto-pilot features engaged in screen but they were not manually activated. Car attempted to cause an accident.

NHTSA complaint #11471459 — an unverified report by a vehicle owner.

POWER TRAIN

Received Error code: VCFRONT_447 indicating a cabin heat issue, and a complete loss of heat within the interior of the vehicle. It appears this also is preventing the battery from fully warming up causing severe vehicle power reduction and lack of regen braking. It being sub-zero and frost bite within minutes this poses a safety risk when traveling. The problem has been reported by other vehicle owners. It has not been inspected at this time. There were no other alerts prior to the issue starting on 1/20/2022 at ~6am CST.

NHTSA complaint #11448216 — an unverified report by a vehicle owner.

POWER TRAIN

Sudden, hard self breaking when in autopilot mode. Danger of collision at high speeds.

NHTSA complaint #11439627 — an unverified report by a vehicle owner.

POWER TRAIN

The car has less than 300 miles on it and I hear a loud clunk under the front of the floor by the pedals as if something is loose like the front motor or the suspension.

NHTSA complaint #11432997 — an unverified report by a vehicle owner.

POWER TRAIN

This problem happens repeatedly. It has been reported by multiple Tesla owners but no action has been taken by Tesla. When driving with the cruise control engaged, the car will brake very aggressively. This happens most commonly when there is no other traffic on the road and no debris on the road. It seems the car believes there is something in front of the car for which it needs to stop, even though the road is clear. But if I press on the accelerator the car resumes normal cruise operation. If there is a car behind me I am worried that the car behind me will crash into me. The braking action is VERY aggressive.

NHTSA complaint #11424607 — an unverified report by a vehicle owner.

POWER TRAIN

THESE ARE ADDITIONAL COMMENTS REGARDING COMPLAINTS NUMBERS 11406321, 11406325, AND 11406632. ACCORDING TO TESLA DOCUMENTATION, LOSS OF PHONE KEY COMMUNICATION SHOULD GIVE 2 TO 3 MINUTES DRIVABILITY TO GET TO A SAFE STOP. THERE WAS NO STATEMENT THAT I FOUND IN THAT DOCUMENTATION TO DESCRIBE HOW THE DRIVER IS NOTIFIED OF THE FAILURE. REGARDING THE STATEMENT BY TESLA PERSONNEL THAT I TRIED TO SHIFT INTO PARK WHILE MOVING, THE CAR DOES, INDEED, PREVENT THAT FROM HAPPENING, AND GIVES THE DRIVER A LOUD AUDIBLE WARNING. THE DATE OF OCCURRENCE LISTED WITH THIS SUBMISSION IS APPROXIMATE.

NHTSA complaint #11406984 — an unverified report by a vehicle owner.

POWER TRAIN

THESE ARE ADDITIONAL COMMENTS REGARDING COMPLAINTS NUMBERS 11406321 AND 11406325. SINCE THAT TIME WE HAVE HAD INCREASINGLY FREQUENT PROBLEMS WITH THE PHONE KEYS ON MULTIPLE PHONES. MY SUSPICION IS THAT THE PROBLEM I INITIALLY REPORTED IN CASE NUMBER 11406321 WAS CAUSED BY LOSS OF COMMUNICATION OF THAT PHONE. I HAVE NEVER BEEN ABLE TO RE-ESTABLISH THAT PHONE AS A PHONE KEY, AND WE ARE NOW EXPERIENCING PROBLEMS WITH MULTIPLE PHONES. I MOST STRONGLY BELIEVE THAT THERE IS A HUGE SAFETY ISSUE WITH THE PHONE KEYS. FAILURE OF THAT BLUETOOTH CONNECTION WOULD RESULT IN THE IMMEDIATE STOPPING OF THE VEHICLE.

NHTSA complaint #11406632 — an unverified report by a vehicle owner.

POWER TRAIN

ON MULTIPLE OCCASIONS WE HAVE LOST COMMUNICATIONS WITH THE VEHICLE THROUGH THE TESLA PHONE APP. THE PROBLEM EXISTS FOR THREE DIFFERENT PHONES OF TWO DIFFERENT MODELS. WE HAVE USUALLY BEEN ABLE TO RE-ESTABLISH COMMUNICATIONS THROUGH THE TESLA PROCEDURES, BUT NOT ALWAYS. ON ALL BUT ONE OF THOSE OCCASIONS THE VEHICLE WAS STATIONARY AND WE WERE ABLE TO USE A KEY CARD TO CONTINUE. BUT ON ONE OCCASION, WHILE MAKING A U-TURN ON A SIDE STREET, THE CAR JUST STOPPED MOVING, PARTIALLY BLOCKING THE STREET. WE HAD LOST COMMUNICATIONS WITH THE PHONE APP. AFTER RECOVERING WITH A KEY CARD WE WENT STRAIGHT TO THE DEALER. EXAMINING THE SOFTWARE, THEY CLAIMED THAT I HAD HIT THE 'PARK' BUTTON WHILE MOVING. FIRST, I WOULD HAVE HAD NO REASON TO DO SO. SECOND, I KNOW OF NO VEHICLE THAT WOULD NOT BLOCK ANY ATTEMPT TO ENTER PARK WHILE MOVING. THIRD, IT KILLED ALL COMMUNICATION WITH THE VEHICLE, WHILE MOVING, LEAVING IT STRANDED IN THE MIDDLE OF THE STREET.

NHTSA complaint #11406321 — an unverified report by a vehicle owner.

POWER TRAIN

THESE ARE ADDITIONAL COMMENTS REGARDING COMPLAIN NUMBER 11406321. WE DID HAVE TO SHIFT INTO PARK IN ORDER TO USE THE KEY CARD. THAT IS NORMAL AND EXPECTED.

NHTSA complaint #11406325 — an unverified report by a vehicle owner.