2018 Tesla Model 3 Electrical Problems

Component/system: The front passenger Occupant Classification System (OCS) in my 2018 Tesla Model 3. The vehicle is available for inspection on request. Description of the failure: The vehicle intermittently displays "Front passenger safety restraint system fault — service required]" on the center touchscreen. The alert first appeared on or about 4 years ago and has recurred approximately ~50 times since. The failure is strongly correlated with cabin temperature. It appears after the vehicle has been parked in direct sun in warm weather, and clears on its own once the cabin cools. It has not occurred in cooler ambient conditions. Safety risk: On this vehicle the front passenger seat uses a capacitive Occupant Classification System rather than a simple occupant-detection pad. The restraint control module uses OCS output to determine both whether the passenger airbag deploys and at what force. When the system faults, I have no way to know whether the passenger airbag is suppressed, will deploy at an inappropriate force for the occupant, or will deploy at all. This directly compromises frontal crash protection for anyone in that seat. I have been avoiding seating passengers there as a result. Inspection and confirmation: The vehicle is outside the basic warranty. Per Tesla's own service documentation, the passenger-side OCS sensor is not individually serviceable; the remedy requires replacing the seat cushion assembly and running a proprietary calibration routine that requires a cabin temperature near 68°F. The vehicle has not been inspected by police, insurance, or any independent shop. Prior warning symptoms: The touchscreen alert described above is the only symptom. There was no prior indication. There is no open recall for this condition on my VIN. Given the number of similar owner reports and the cost of the remedy, I believe many affected vehicles remain unrepaired and in service.

NHTSA ID

11752890

Incident

Jul 1, 2026

Vehicle displayed a “Safety Restraint System Issue - Service Required” alert (fault codes RCM_a056 and RCM_a032). Tesla diagnosed an open circuit between the driver-side curtain airbag and the left airbag controller, requiring replacement of the left body harness. Tesla quoted approximately $1,800–$2,200 for the out-of-warranty repair. This is a known, recurring pattern — multiple other 2018 Tesla Model 3 owners report experiencing this identical fault at nearly the same mileage (~78,000 miles), suggesting a design or component wear issue rather than isolated damage, similar to a prior Tesla trunk-harness recall (NHTSA campaign 21V-00D) that also stemmed from a wiring/harness defect on this same vehicle. I am requesting NHTSA investigate whether this represents a safety-defect trend warranting a recall.

NHTSA ID

11750017

Incident

Jul 1, 2026

High voltage fast charge contactors experienced partial weld failure (BMS_a167_SW_FC_Partial_Weld) during routine Supercharging, causing complete HV system shutdown (hvState = HV_DOWN). Vehicle also threw BMS_a085/a086 Pack and Fast Charge Contactor Mismatch codes. Tesla service is refusing to cover repair under the 8-Year HV Battery Warranty, claiming fast charge contactors are not a warranted component despite being integrated into the HV battery assembly. Vehicle has been at Duluth, GA Tesla Service Center since approximately June 8, 2025.

NHTSA ID

11743421

Incident

Jun 7, 2026

It showed message that emergency brakes not available. It was related to wire hardness inside the trunk lid. I had to get it replaced. Tesla did not cover it.

NHTSA ID

11740870

Incident

May 1, 2026

The contact owns a 2018 Tesla Model 3. The contact stated that while opening the doors of the vehicle, the driver's side seat back unintendedly reclined and pressed down on the rear seat, causing the cushion to become deformed. The contact manually used the seat controls to return the seat to an upright position. There was no warning light illuminated. The contact stated that the failure was intermittent and only occurred while the doors were opened. A Tesla service center was contacted; however, an appointment was not scheduled for diagnostic test. The contact was provided an estimate for the repair. The vehicle was not diagnosed or repaired. The failure mileage was approximately 95,000.

NHTSA ID

11730362

Incident

Apr 7, 2025

Mileage

95,000 mi

The contact owns a 2018 Tesla Model 3. The contact stated that there was a feature in the vehicle that allowed the front driver’s seat to automatically adjust according to the saved driver's profile. The contact stated that the driver’s seat back and forth movement to adjust to each driver's profile might have caused loose wire connection, resulting in error code: RCM_a021 (Front Left Safety Restraint System Fault) being displayed. The contact stated that the error message had been displayed intermittently. Upon investigating the failure online, the contact related the failure to the seat adjustment feature. The failure was reported to the manufacturer through the Tesla App; however, the contact had not yet received a response. The vehicle was not diagnosed or repaired after the failure. The failure mileage was approximately 55,000.

NHTSA ID

11730125

Incident

Dec 9, 2025

Mileage

55,000 mi

Error code RCM_a021 front left safety restraint system fault. An issue that arises purely due to poor seat design. It is the fault of the seat pinching a wire from moving back and forth. This safety issue is an inevitability and not a one off chance. This issue is publicly noted on forms throughout all the years of this car’s production. This error results in airbags not being properly deployed in the event of an accident and the car not properly reading the passenger occupancy.

NHTSA ID

11724519

Incident

Oct 16, 2024

Description of the Defect: While driving with Full Self-Driving (FSD) engaged, the vehicle's primary computer shuts down and reboots, causing a sudden loss of all safety features, including Blind Spot Monitoring, Lane Departure Warning, Forward Collision Warning, and the driving visualization. The cameras go black while the vehicle is in motion. The Trigger: The failure is triggered by high electrical load. If the Cabin Heater (HVAC) and Seat Heaters are active while FSD is fully computing, the 12V power supply to the computer drops below critical voltage, causing a "Turbo A" processor lockup and system crash. Evidence of Defect: Service Center diagnostics confirmed the specific error code APS_w169_TurboA_SCS_LKUP (Computer Crash) occurred at the exact same timestamp as VCLEFT_a302_blowerGeneralFault (HVAC Blower Failure). This proves a common-mode voltage drop affecting multiple critical systems simultaneously. Manufacturer Response: The manufacturer (Tesla) acknowledged the logs but refused to inspect the wiring harness or ground connections, instead recommending a replacement of the computer unit. However, the failure can be mitigated by unplugging external cameras to reduce load, proving the root cause is an insufficient power delivery design (Wiring/Grounding) rather than a component failure. The computer is running at full load with the newest FSD software and it can no longer keep up with additional loads. Safety Risk: This defect causes a sudden, uncommanded loss of driver assistance and situational awareness tools (cameras/visualization) while the vehicle is maneuvering in traffic. The vehicle’s power distribution system appears insufficient to support the electrical load of the software (FSD) and the hardware (HVAC) simultaneously.

NHTSA ID

11716395

Incident

Nov 10, 2025

After downloading Tesla’s update (no. 2025.44.25.4) software my heater (with the window defrost functionality) in winter stopped operating. I made my update while at my nearest Tesla service compound (location verifiable per system location log) on 01/25/26 when that same day software began throwing HVAC error codes with blowing cold air, when previously my heat ran well. This is not coincidental; this is system design failure.

NHTSA ID

11714886

Incident

Jan 25, 2026

Please review attachment.

NHTSA ID

11709559

Incident

Jan 7, 2026

The center display (Vehicle Pad) on my 2018 Tesla Model 3 went completely blank while driving. This eliminated access to all vital driving information including the speedometer, gear selection, and safety indicators. Safety Concern: Without visible speed data and wipers the vehicle cannot be operated safely or legally. I attempted to reboot the system and power cycle the vehicle but the screen still failed.

NHTSA ID

11694004

Incident

Oct 6, 2025

No warning messages at all, all cameras/sensors stopped working all at once while driving, full self drive stopped working, lane assist, safety features of full self drive was degraded by this. Car software v12 (2024.44.25.2 288ce84bb43e), according to the dealership the computer fried randomly.

NHTSA ID

11691825

Incident

Aug 9, 2025

The contact owns a 2018 Tesla Model 3. The contact stated that when the vehicle was started, the GPS failed to function as intended. In addition, the “Unable to Charge” warning light was illuminated. The contact stated that the GPS provided incorrect directions. The contact attempted to recharge the battery; however, the battery failed to charge. The contact stated that the failure had occurred the following day after an over-the-air software update was performed. The dealer was made aware of the failure. The contact was informed that the battery needed to be replaced. The vehicle was not repaired. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. In addition, the contact referenced a document that stated that the battery life should last 200,000 to 300,000 miles. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 106,884.

NHTSA ID

11690825

Incident

Oct 1, 2025

Mileage

106,884 mi

I believe my car should be included in the recall for trunk harness recall. My alert and issue is the rear camera being off due to rear trunk ruining the wiring harness that has affected many cars. This is already a recall but I believe my car missed being involved.

NHTSA ID

11690203

Incident

Aug 8, 2025

The contact owns a 2018 Tesla Model 3. The contact stated that while driving 60 MPH with the Self Driving feature activated, the vehicle failed to slow down while approaching oncoming traffic. The vehicle accelerated and drove around the traffic. The contact depressed the brake pedal and touched the steering wheel to disable the Self Driving feature, but the vehicle failed to respond. The contact stated that once the vehicle passed through traffic, the brake pedal was depressed again, and the Self Driving feature was deactivated. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was 55,866.

NHTSA ID

11685213

Incident

Aug 13, 2025

Mileage

55,866 mi

Main incident: Time: 2025-08-28 ~12:41 PM PST What happened: After searching for a parking space, the driver was preparing to reverse into the spot, the driver pressed up the stalk to shift the gear into reverse, a sound was heard and something showed up on the screen, the vehicle once again started accelerating and running forward suddenly and sharply (3 mph to 28 mph in 3 secs), driver tried to steer the vehicle away from cars and buildings to minimize danger, the car rushed onto a concrete curb, hit one blue Tesla, then hit the side of a concrete utility pole, and ran over a plant and last crashed into the chain-link french before it finally stops Injuries: * Spine pain for one passenger Damages: ** All tires blown out, tire falls off ** Severe damages throughout the vehicle body * One Tesla parked on the parking lot was severely damaged * The utility pole's base box was scraped and deformed * One plant was knocked down Similar case 3 few mins ago: Time: 2025-08-28 ~12:38 PM PST What happened: The driver entered a oneway parking lot, but found no available spot and was trying to back up, the vehicle suddenly accelerated on its own. The driver performed an emergency brake and stopped the vehicle. At the time the vehicle stopped, it was only about 20 inches away from two cars in front of it Injuries and damages: None What component or system failed or malfunctioned, and is it available for inspection upon request? Malfunctioning of the electronic control or braking system leading to abnormal acceleration Conflicting gear shifting and autopilot engagement design The right stalk is used to both shift gears and engage autopilot features, this design makes it very easy for the system to confuse the two actions Autopilot feature safety issues Autopilot features (whether its FSD or cruise control) should not be allowed to initiate abrupt acceleration to a dangerous speed in a low speed area (for example parking lot) Insurance claim filed, number: 25-647243342

NHTSA ID

11684449

Incident

Aug 28, 2025

Tesla failed to properly diagnose a high-voltage battery isolation fault in my 2018 Model 3. Despite safety-critical BMS_a027 and BMS_a142 faults indicating multiple isolation failures, they skipped required insulation resistance testing, falsely blamed sand in a connector, and charged me $174.95. After the issue returned, they reversed course, replaced an internal battery contactor, and reduced the $1,173 estimate to $356—admitting fault without owning it. Days later, a diagnostic showed dangerously low isolation resistance (380kΩ, far below Tesla's 1,000kΩ safety threshold), yet they took no further action. On July 12, the car again went into limp mode. Tesla’s repeated failure to follow safety protocols, diagnose accurately, and honor warranty obligations has left me with a vehicle in an unsafe state and no corporate accountability. I've contacted their Resolutions team three times (7/2, 7/7, 7/10) with zero response.

NHTSA ID

11673763

Incident

Jun 11, 2025

My brake lines began to leak. When I took the car to the Tesla Service center they repaired the brake lines, but in the process they found that the brake fluid had leaked in/on the battery compartment. Furthermore, they found a coolant leak that also leaked on/in the battery compartment. This cause a hole to develop into the battery compartment. Having the coolant and brake lines in a place that could affect the batteries is a significant design flaw of the Model 3. According to the technician from Tesla, my car/batteries, were a ticking time bomb and could have ignited at any point. I am very fortunate that a fire was not started with myself or my family in the car. I believe Tesla needs to make all Model 3 owners aware of this possibility and come up with a way to remedy this flaw before someone looses a life. If the brake lines on my car hadn't sprung a leak, I'm not sure I would have know about the coolant leak until it was too late.

NHTSA ID

11666979

Incident

May 27, 2025

This is a large scale problem with Tesla due to their "easy entry" which automatically moves the front seats to fit the drivers saved positions. Due to Tesla not properly securing the wires under the seat, they get crimped over time causing an error of "safety restraint system issue." There have been thousands of reported Teslas with a simple Google search. The service center also stated to me this is a large scale issue but a recall has not been issued. This is very dangerous as this disables the airbags due to a seat belt or wire crimp under the seat issue. Please investigate and issue a mandatory recall for the safety issue as Tesla wants $1000 to rectify the issue. Many have reported this issue to be fixed by the service center multiple times only to come back months later.

NHTSA ID

11666623

Incident

Jun 12, 2025

I just traded in my vehicle for a Tesla from 3rd party dealership on [XXX] A light came on once I reached my home. I called right away before the dealership closed but no one answered. So I took it upon myself to make a service call to Tesla to get my vehicle checked come to find out my vehicle has extensive damages from my unit drive, my subframe and the battery pack is severe punctures and needs to be replaced. Choice Automotive LLC in Honolulu Hawaii didn’t disclose anything to me before purchasing this vehicle. also they didn’t disclose that this vehicle was in a car accident, but they carried on with the sale. I have pictures of what needs to be repaired. Tesla said, I will need $20,000 to repair these damages. So I’m trying to take legal action against Choice Automotive LLC for selling me a vehicle that needs a lot of repair to drive normal again. I need them to pay for these repairs immediately. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11658029

Incident

Mar 27, 2025

My 2018 Model 3 recently started experiencing issues during AC charging where I’m only able to use 16A out of the 48A available from my Tesla mobile connector charger at home. The specific error warning and error I’m seeing says “PCS_a019 Power grid or vehicle issue limiting AC charging Unplug and retry/ Try different charging location”. Before this started happening I’ve been charging with the same charging setup at home since 2019 and have been getting 32A consistently.
I’ve tried the following options to diagnose the issue: 1. I’ve unplug and replug mobile charger from the connector. (the end plug to the mobile charger), I’ve also plug and unplug connector to the nema 14-50 receptacle. 1. The mobile connector exterior shows a constant flowing of green color on the “TESLA” letters outside the charger 2. I also separately own a second 2023 Model Y Performance, my Model Y is able to use the same Tesla mobile charger connector/receptacle at my home. It it getting AC charging at 32A 3. I’ve also tried charging the 2018 Model 3 (w/ the issue) at another separate AC charging station from a friend’s house that can normally deliver 48A, but I’m still also only getting 16A out of the possible 48A After sending the above to Tesla service center, they remotely diagnose and stated that it was an partial failure/issue with the " Power Conversion System" on the vehicle. However, Tesla mentions that is is not covered by their "HV Battery Warranty" and only covered by their 4 year 50k miles Basica vehicle warranty. My particular vehicle has only 37k miles on the odometer but it exceeded the 4 year period so I'm out of warranty. However I found that my vehicle fits the criteria for this outstanding NHTSA bulletin notice (SB-18-16-011) [XXX] , which also specifically mentioned "Replace Reworked Power Conversion System". My vehicle meets the criteria ( manufactured [XXX]) but Tesla refused to honor the bulletin. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11656795

Incident

Mar 21, 2025

1. PTC Heater, old part is available for inspection 2. PTC heater failed while driving, experienced loss of power and slow loss of secondary electrical systems (the 12v battery was not able to recharge itself with the PTC heater not functioning). When attempting to restart car after pulling into a parking lot, the entire car died (12V battery was drained so it couldn't start up) and had to get towed to Tesla service center. PTC heater is critical for car to operate as it is closely linked to 12V battery. Additionally, without PTC heater car cannot defog windshield, resulting in potentially poor visibility. 3. Dealer replaced the defective part (PTC heater) and had to replace 12V battery as well. Was not covered under warranty and I had to pay the cost out of pocket. 4. Inspected by manufacturer and replaced. 5. Got warning signs about reduced power available, and secondary electrical features were limited.

NHTSA ID

11652498

Incident

May 12, 2024

1. The Power Conversion System (PCS), still in the vehicle and not available for inspection 2. 2 of the 3 controllers have failed, resulting in limited AC charging (16A out of 48A max). The PCS helps regulate AC and DC electricity and connects the 12V batter to the HV battery. If it fails, it could lead to dangerous situations since the electricity from the HV battery wouldn't be as controlled. I'm worried that if the final controller fails while driving it could lead to a loss of power. 3. Problem throws an error code when charging that the dealer has verified, they will not replace it unless I pay for the part+labor which is roughly $1,800. 4. Vehicle inspected by dealer, they will only fix if I pay for replacement part. 5. Car has warning message when charging.

NHTSA ID

11652488

Incident

Mar 1, 2024

RCM_a021 alert: Front left safety restraint system fault. Seems like an issue caused by seat movement back & forth.

NHTSA ID

11651400

Incident

Mar 25, 2025

Power Coversion System (PCS) failed on vehicle Causing issues with charging No User facing errors to alert of issues prior to problem (hidden in service menu) - preventing owners from claiming under basic 50k mile warranty. Stated as not part of HV Battery warranty and replacement is ~$2000 Advised to replace or could leave car unusable.

NHTSA ID

11642714

Incident

Nov 1, 2024