2021 TESLA MODEL 3 Complaints
View complaints related to 2021 TESLA MODEL 3. The complaints found here are submitted by actual consumers with first hand experience. There are more than 640 complaints submitted for the 2021 TESLA MODEL 3. You can submit your own complaint to the NHTSA or call the Hotline, Monday-Friday 8am to 8pm at (888) 327-4236, TTY: (800) 424-9153.
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2021 TESLA MODEL 3- Sacramento, CA
- The rear middle seatbelt became locked and will not unwind or extend. The seatbelt remained stuck in the retracted position, making it unusable. The vehicle and seatbelt assembly are available for inspection upon request. However, Tesla has already fixed the issue, but I feel we were wrongly charged because I believe this should be a recall. I searched this issue online, and others have reported the same issue. Because we rarely have the need to use our rear seats, it wasn't until years later we discovered this issue. - Because the rear middle seatbelt cannot be extended, that seating position cannot safely be used. Any passenger sitting in that position would not have a functioning restraint system in the event of a collision, creating a safety risk. - Yes, Tesla service inspected the vehicle and confirmed that the rear middle seatbelt was locked and not functioning properly. - The vehicle has been inspected by Tesla service. It has not been inspected by police, insurance representatives, or other third parties. - No warning lights, alerts, or messages appeared prior to discovering the issue. The seatbelt was found to be locked when we attempted to use it, and it would not extend.
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- Williamsburg, VA
The vehicle is undriveable due to a high-voltage enable safety lockout triggered by ECU identity/MAC mismatch after a software/update window; local service instructed me to ‘safely disregard’ active safety alerts contrary to vehicle telemetry, creating a safety risk. Chronology (key timestamps) • Jan 28, 2026 — Low-voltage undervoltage precondition recorded (DIF_a018). • Feb 2nd, 2026 — Low-voltage undervoltage precondition recorded (DIF_a018). • Feb 03, 2026 08:46 — Identity/MAC invalidation alerts (CP_a089 / CP_a077); HV-enable blocked cascade. • Feb 24, 2026 — Service app: estimate approval prompt; supervisor instruction to ‘safely disregard’ active HV alerts captured via screenshot. • Feb 27, 2026 — Persistent handshake stall (CP_a066, State B1) despite ‘successful’ software job and new firmware update to patch the 2026.2 tree branch software. Vehicle remains grounded. Safety Concern Vehicle telemetry states HV contactors are blocked to protect the vehicle; service staff advised to disregard active alerts. Inconsistent guidance risks unsafe operation. I grounded the vehicle pending engineering review. Troubleshooting and A/B Tests My home EVSEs successfully charge a different Tesla (Model Y). The subject VIN charges at DC fast charging (Supercharger) and once on a third-party EVSE, but fails on my two home EVSEs thereafter. This localizes the issue to vehicle-side AC charge path/charge-port logic rather than the EVSE. Request OEM to provide CP waveform under load + Toolbox logs. Please log this safety-related defect; aggregate with similar complaints, and, if appropriate, open an investigation into identity/integrity faults causing HV-enable lockouts and conflicting service guidance
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- Warren, MI
The rear camera malfunctions intermittently and causes other errors to happen, like Automatic emergency braking unavailable or forward collision warning unavailable. When the camera error happens, it says the camera is unavailable. I took my car to the Tesla dealership three times. The first time, they did a continuity check and said the harness was degraded, and they replaced the harness and the rear camera. A week later, it happened again. The second time they reset the camera calibration and it worked. The day after, it happened again. The car is at the Tesla dealership for the third time (02/20/2026).
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- Sahuarita, AZ
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.
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- concord, CA
I wrote several months ago about my 2021 tesla model 3 that the rear doors do not have any mechanical door handle release and is a big safety concern also how can a manufacturer get away with this and also not informing the consumer that anyone sat in the back may perish if involved in a accident and can't get out.
Source: NHTSA WEB SITE -
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2021 TESLA MODEL 3- Fremont, CA
Full self driving system (fsd) has ran a red light twice. It slows almost to a stop then takes off.
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- Cerritos, CA
The driver’s side belt makes a “click” sound when latch is inserted into the locking component but at times does NOT remain lock and the belt is released shortly after. The issue is sporadic. The belt is released with a low amount of force i.e. adjusting the body in the seat or twisting body to look over the shoulder
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- Campbell, CA
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.
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- brooklyn park, MN
HVAC system went out at 7500ish miles. It was repaired under warranty, and a "fix" was administered through software by tesla. My HVAC has gone out again at 84k miles FOR THE SAME REASON. about 77k miles after it was just repaired. Quick check online. this is still a very common issue. No heat creates a significant safety hazard due to lack of the ability to defrost the vehicle or frost building up on cold days.
Source: NHTSA WEB SITE -
2021 TESLA MODEL 3- San Francisco, CA
To Whom It May Concern, I am submitting this complaint to report a serious and potentially dangerous safety defect affecting my 2021 Tesla Model 3 Performance. After exposure to heavy rain or wet conditions, the vehicle’s horn completely stops functioning. The failure occurs regardless of the activation method—neither pressing the steering wheel horn nor using the horn via the mobile app produces any sound. The horn remains nonfunctional even though the vehicle is otherwise operable. This issue has occurred after the vehicle becomes wet due to rain and appears to be related to moisture intrusion or an electrical/design flaw. Once the failure occurs, the driver fully loses the ability to use the horn for warnings or emergency signaling. This is a critical safety concern. The horn is a federally required safety device and is essential for alerting pedestrians, cyclists, and other drivers to avoid collisions. Losing horn functionality significantly increases the risk of accidents, especially in urban driving, highway merging, and emergency situations where immediate warning signals are necessary. This issue is not isolated to my vehicle. Numerous Tesla owners have reported the same horn failure after rain or wet conditions on online forums and owner communities, indicating a widespread and systemic defect rather than isolated wear or misuse. Given the safety implications and the volume of similar reports, I respectfully request that NHTSA investigate this issue to determine whether a design or manufacturing defect exists and whether corrective action or a recall is warranted. Thank you for your attention to this matter. Owner – 2021 Tesla Model 3 Performance
Source: NHTSA WEB SITE