2021 Tesla Model 3 Powertrain & Transmission Problems

HVAC system which provides cooling/heating for all the systems including the powertrain, battery, inverters, Full-Self Driving computer malfunctions randomly shutting itself off due to a known issue of failing pressure and temperature sensors. Tesla is aware of this issue where the sensors may fail prematurely and in 2021 they issued a service bulletin SB-21-18-002. I was told It would be fixed with a software update... In other words it was never fixed. Now my car says that cooling and heating may randomly be unavailable due to invalid readings from the pressure and temperature sensors. They want me to pay to have the sensors replaced despite them acknowledging that they have a defect causing premature failure. This issue is safety related because in the event that I was supercharging and the HVAC system shuts down it could potentially lead to a battery fire or thermal runaway. Not to mention that the car left me without heat in subzero temperatures on a roadtrip.

The high-voltage traction battery pack has failed twice on my 2021 Tesla Model 3, both times while the vehicle was under the original battery warranty. The failures occurred on: • 08/30/2022 at approximately 15,100 miles • 11/08/2025 at approximately 57,222 miles The exact error code by Tesla was bms_a079, which doesn’t let the vehicle charge at all. The vehicle was drivable before the battery depleted. The defect has been reproduced, confirmed, and repaired by the manufacturer twice, but the same critical system has failed again after replacement, raising concern of a recurring defect. The failed component is the high-voltage battery pack. The component was inspected by Tesla, and in both cases Tesla confirmed battery failure and replaced the entire HV battery pack with a remanufactured unit under warranty. The failed components were retained by Tesla and are available for inspection by the manufacturer.

my 21 M3P 27K miles threw BMS_a079 I've never used a supercharger and rarely charge over 80% mostly charging at work on lvl 2 & occasionally at home on lvl 1 vehicle will no longer charge I've tried 2 Button reset and HV disconnect no help. 27k miles seems unreasonable for a battery malfunction on a vehicle that has been cared for meticulously.

The contact owns a 2021 Tesla Model 3. The contact stated while his wife was driving at approximately 29 MPH, the vehicle independently accelerated and the front of the vehicle crashed into a tree, where it came to a stop. No warning lights were illuminated. The front driver's side air bag was deployed. A police report was filed. Medical attention was sought as a precaution; however, there were no injuries sustained. The vehicle remained at the residence. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 80,340.

The vehicle, a 2021 Tesla Model 3, had an episode of sudden unintended acceleration. I was almost stationary waiting to make a left when the car accelerated by itself, left the road, crossed a grass field at high speed and crashed into bushes. The vehicle was not on auto pilot, it resulted in damage of almost $ 20.000 as estimated by insurance. The vehicle is available for inspection, it will be checked by Tesla service after the damage is fixed. There were no previous warnings, this is the first incident of this kind. It is not clear what component malfunctioned, probably some electric/electronic device in charge of acceleration. It was obviously a very dangerous event that could have jeopardized my safety and/or some others.

While drive after dark on a four-lane city road with no breakdown lane my vehicle alerted me of a problem and I should slow down. About five second later the car came to a stop and placed itself in park in the right-hand lane with traffic coming up behind me at 50 MPH. I was unable to locate the emergency flasher so I turned on the turn signal (I later found out the emergency flasher was located on the ceiling with white marking which were not visible in the dark). With the right turn blinker on I attempted to exit the vehicle but when I did, the turn signal turned off. This left me with a choice to leave a dark vehicle in the right-hand lane with moderate traffic or sit inside keeping the lights and signals on. No accident resulted but this was a very dangerous situation. The failure was a power converter which led to the disabling of both the front and rear drive motors. I was also unable to put the car in neutral and move it as far right as possible. I would have expected this type of failure to at least turn on the emergency flashers and give the driver the option of placing the car in neutral so it could be moved off the road. When i bought the car I specifically ordered the one with front an rear drive motors so failure of one would not completely shut down the vehicle. Seem like this power converter is a single point failure which leave the operator and other vehicles in a very dangerous situation.

My 2021 Tesla Model 3 shuts/powers down WITHOUT warning while driving with a battery charge >0%. This unsafe event has occurred twice now! While the battery gauge displayed 10%, I was driving about 60mph when all of these warning messages appeared prompting me to pull over. As soon as these messages displayed, my car lost all propulsion and I was left stranded in the middle of the road. Both times I narrowly avoided being hit by other vehicles traveling at high speeds since my car died in the roadway. The car was towed to Tesla on both occasions, and they weren't concerned about my safety issue in the slightest. Instead, they said the battery just ran out; however my car displayed that I had about 6-10% charge remaining. So, if the battery were completely depleted (like Tesla says), then the meter should have displayed a 0% reading at the time of the breakdowns or, there is something defective with the battery/computer. Tesla service has refused to investigate the cause of the safety issue and, thus, refused to replace the EV battery (even though my car is still under the manufacturer's warranty). Electric vehicles should not die/run out of battery at 10% charge. However, my EV has done so TWICE! Tesla says that I just ran the car out of battery but has no response when I show them the pictures and video proving that the car died when there was, in fact, a decent amount of charge remaining on the vehicle (PLEASE SEE ATTACHED VIDEO AND PICTURES). If your phone died at 10%, then you would take it back to the manufacturer and demand that they fix the defective product. However, Tesla refuses to help fix my defective vehicle and just tells me that it is "operating as intended". EVs should not just lose all propulsion mid-drive. This creates an unsafe vehicle for me to drive, for my two young daughters in their car seats, and for other drivers who might hit me. I can provide other Tesla owners who have had a similar experience. Please force Tesla to take action!

On May 22, 2023 driving south on I-580 through Reno with the Tesla adaptive cruise control, there's a 55mph construction zone. As a result, I use the right scroll wheel to adjust the speed from 65 to 55mph. The scroll wheel didn't work. As a result, I turned off the cruise control with the right steering wheel stalk. At the same time, I noticed the vehicle speed indicator on the upper left of the CRT display was malfunctioning; both failing to respond to changes in the car's speed, and then indicating erroneous speeds (at one point indicating 34mph when I was going around 60mph. These issues continued. I took the exit on Double R Blvd to turn right. As I got into the right lane on the freeway to exit I attempted to turn off the cruise control and it didn't work. Approaching the exit, I then applied the brake. The regenerative braking function did not apply. As a result, it felt like the cruise control didn't turn off. However, I braked to a stop at the intersection in the right lane with no issues. When the traffic cleared, I attempted to turn right and proceed east on Double R Blvd. The car didn't move. Using the right stalk, I tried shifting into drive, reverse, and back. All this time, the drive (D) and reverse (R) indications on the CRT did not show. I let off the brake and the car inched forward. I turned right immediately into the Maverick gas station entrance to get off RR. The CRT display now showed the back-up camera displays (a normal indication of the car being in reverse). I cautiously let off the brake and applied the accelerator pedal to see if I backed up, but the car was in drive and proceeded normally. I continued to drive and the CRT screen went completely black. I soon realized the car's computer was rebooting with the faint Tesla logo on the black screen. Within a mile or so, everything came back on the screen and worked normally. I then reached my destination. When I returned to the car, it was as if nothing had happened.

The adaptive cruise control (Tesla "autopilot") system has unexpectedly disengaged and applied light to heavy braking numerous times. The system frequently mistakes a particular highway sign for a stopped vehicle and applies moderate braking. The system has also applied light to heavy braking in circumstances where I simply cannot figure out what the camera is interpreting as a hazard. This puts me and other drivers around me at risk as it is unnecessary and unpredictable braking at highway speeds in traffic. Tesla has not been able to remedy this problem and I do not consider the cruise control system to be safe to use. This has happened more than 10 times.

While driving, a small warning appeared on the screen, directing us to pull over. Roughly 10-15 seconds later, the car died in the middle of the road. The car was towed to a Tesla service center. The rear motor power inverter was replaced. Incidentally, I saw this news story today: https://www.autoevolution.com/news/tesla-recall-for-127785-model-3s-in-china-due-to-rear-motor-inverter-defect-185844.html The way the car failed was very dangerous. My other complaint was that the user experience telling us to pull over was not sufficient. If the problem was that dire, we need much more dramatic audible and visible alerts, as well as an indication of how long we have to go. We could have pulled off into a safer spot if we knew we only had a few seconds.

While driving the vehicle using autopilot or adaptive cruise control, the vehicle "phantom brakes" - meaning the vehicle abruptly applies the brakes to slow down even though there are no obstacles in the road. This happens almost every time either one of these systems is used.

While parked, as I selected "R" (reverse), the car lurched and displayed two warning messages: "Rear motor disabled - safe to drive" and "Vehicle shutting down - PULL OVER SAFELY". The drive train was locked up and I fear that if the car had been moving when this happened, it would stopped suddenly possibly causing an accident. The car was towed away.

When driving with the adaptive cruise control on, the car will for no reason, briefly slam on the brakes for no reason. I have almost been rear ended twice because of this. check mark box above in this web page would not allow me to check the adaptive Cruise Control item.

When I was driving on highway the suddenly I lost power and if I press gas pedal it would not go. I applied brake to slow down and pull over but as soon as I applied the brake it corrected on its own and continued to go since I did had similar issue like this previously I called Tesla and asked them to tow it to the shop. This is the 3nd time that I'm having an issues with drivetrain that my car was towed to shop.