2019 Tesla Model 3 Seat Belt Problems

Mileage when the problem started

Owner reports

Selected complaints filed with NHTSA by 2019 Tesla Model 3 owners, lightly cleaned up (personal details are redacted by NHTSA).

I started to having "Faulty Restrain system fault" around 49k miles on Tesla Model 3. Error pop up "service needed". Consult Tesla for repair. First they ask for $384 for repair harness wires attach for driver front seat. Upon checking warranty on Tesla.com, it provides 60000 miles and 5 years warranty for Restrain System coverage so tesla agrees to fix error for "$0". Upon taking car for repair, I was informed I had rodent cause damage (chewed) wires and it's not cover. I had to pay $180 for repair. I live in Phoenix city and where I live we don't have any problem with rodents. It's very shocking to learn that rodent get access to underneath of Tesla and can chewed on wires. Why wires are not covered with better material rather than cheap plastic tapes. Those wires play significant role in vehicle safety as far as restrain system is concern. …

I am submitting a complaint regarding an unresolved safety issue with the front passenger restraint system in my 2019 Tesla Model 3 (VIN: [redacted] ). Since February 2024, I have encountered recurring alerts for this system, despite multiple service visits to address it. Service History and Concerns: The initial repair attempt on February 27, 2024, involved Tesla replacing the Occupant Classification System (OCS) filter module. However, the alert returned shortly after, showing the issue was not resolved. On October 14, 2024, I returned to Tesla, where they quoted $1,800 for further repairs, claiming my general warranty was expired. Their records indicate that this failure directly impacts the front passenger's safety restraint, making it a serious defect. During a follow-up visit on October 23, 2024, the issue was confirmed but left unaddressed unless I paid out-of-pocket. …

To Whom It May Concern, I am logging a safety defect complaint regarding my 2019 Tesla Model 3, which displays active fault code RCM_a056 - Front passenger safety restraint system fault. This error deactivates the front passenger airbag and seatbelt pretensioners, creating an immediate, severe safety hazard. The Defect: The failure involves the Occupant Classification System (OCS) seat sensor and affects passengers in two ways: 1. Children (Current Stage): The fault triggers primarily when a child sits in the front seat. The degraded sensor mat cannot process lighter weight accurately, throwing an "implausible voltage" error that disables the airbag system. 2. Adults (Advanced Stage): online data shows this same code eventually locks out for adults due to internal wiring harness fraying or sensor circuit failure. …

It was raining and my passenger got in the car (slightly damp). When he sat down, I reveived an error message on the screen saying "Front passenger safety restraint system issue". The airbag light is red indicating that it won't work for my passenger. You should be able to get into a car wet without your airbag no longer working. My understanding is that this is a common problem. Tesla wants > $1000 to replace the seat sensor + requires me to pay to have my airbag replaced so the part matches the sensor. According to Tesla Service Bulletin SB-23-20-002, the new style of seat sensor is strictly incompatible with the older style of airbag (known as a "Full Suppression" airbag). $182 (Diagnostic Fee) $475 (OCS Replacement) $318 (Airbag Update) + Labor + Tax The internet is full of reports of this issue. Just google "Front passenger safety restraint system issue". …

On October 25, 2025, the vehicle suddenly displayed an alert stating that the front left safety restraint system required service. The failure involved the front left seat harness, where a broken wire connected to the lap pretensioner squib caused the restraint system to malfunction. As a result, the driver's seat belt pretensioner may not deploy correctly, putting occupant safety at significant risk in a crash. There were no warning signs prior to the alert. The problem was inspected and confirmed by a service technician, who documented the broken harness wire and noted that the harness inspection failed before replacement. The defective component was removed and replaced, and the alert cleared after the repair. The part is available for inspection if needed. …

Alert RCM_a021pretenLapFrontLeft. Caused by the seat harness wires being pinched and stretched when moving the seat back/forward/up/down. Eventually the wires are damaged by the seat movement. Tesla has touted a feature called "Easy Entry" which moves the seat to a preset position to allow the driver to get in and out of the car more easily. This moves the seat lower and farther back and then moves the seat back up to the driver's position when ready to drive. This increased seat movement, every time the driver gets in and out of the car, causes the wires to wear prematurely and the above fault to trigger. In the event of an accident the driver side airbag may not deploy and/or the seat belt pretensioner may fail to lock the seat belt in place, leaving the driver exposed to serious potential injury risk. …

After owning my new car for less than 5 years I started intermittently receiving a "Safety restraint system fault" error. It seemed to most frequently occur when the driver's seat was raised. When lowering the seat the error would often go away. Checking the service menu's notifications there was RCM_a021 code. I researched online and found the following thread which exactly described my problem: [redacted] I opened up the connector and one wire was cut. I restripped and soldered it and the error went away. I consider this a safety issue since through normal use of different seat positions (including the easy entry option) the wire bends and gets cut, which causes the seat belt safety features to stop working.

The car's main screen displayed an error message, "front passenger safety restraint fault. service required." According to on line user groups this same safety system fault has occurred in many Tesla Model 3 cars. In my case, Tesla replaced the occupancy sensor harness in the seat and replaced the passenger side air bag, for a total price of $1800. Replacing the air bag was by far the most expensive part of the repair, but it wasn't defective, it was merely incompatible with the new sensor. With a repair this expensive, many car owners will be tempted to forego the entire repair, since the warning doesn't prevent the car's operation. Tesla should recall all Model 3s and repair the problem, otherwise many drivers will be tempted to drive with a defective sensor system.

Driving as normal when an alert for a front passenger safety restraint system fault appeared. It went away on its own. I thought it was a software glitch. It would periodically reappear, then go away after a driving session. Last week it persisted between sessions. I learned that if the seat was moved slightly forward or back, then the alert would go away. I scheduled a service with Tesla. Tesla advised that the entire car seat and airbag would have to be replaced for $1800. This is a ~50,000 mile car with no collision history. It's just out of warranty. Tesla refuses to tell me if the car will safety function in an accident or not. The alert is gone, but I have a service estimate that says the car has all of these problems. Major safety concern.

I received a notice onscreen (photo attached) that says "Front passenger safety restraint system issue, Service is required." I did some research online and a number of other owners of 2019 Tesla Model 3 vehicles have received this warning, which involves a malfunction that is a combination of the front passenger seat belt, air bag, and seat sensor for the air bag. A number of people with this year and make have gone to Tesla, and Tesla service workers have said "this a known issue" for this year and make. Since this issue involves a number of safety components, and is a known issue, Tesla should be required to fix this as a product defect recall. Instead, they quoted multiple owners, including myself, approximately $2,000 to fix.

Related recalls

Seat Belt complaints in other Model 3 years