Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2018 Tesla Model 3 owners, lightly cleaned up (personal details are redacted by NHTSA).
I was at a stoplight behind a Toyota Tacoma. I must have stopped around 8 feet behind it. I was not using FSD and I was not one-pedal driving. My foot was on the brake. I must have been at a complete stop for approximately 10 seconds when my Model 3 suddenly accelerated full throttle on its own and rear ended the Tacoma, directly hitting its trailer hitch, causing my car's driver-side airbags to deploy. When it happened, the light was still red and my foot was still on the brake. I never touched the accelerator. Luckily I was driving alone. After the inital contact, my car sort of bounced off of his hitch then slowly lurched forward before it stopped. After that, it was immobile, leaving me stuck in traffic until it was towed away.
Power Conversion System was defective when car brand new and replaced under 50k mile warranty. Now out of 50k mile warranty and Power Conversion System is failing again. Manufacturer service center says this item is customer pay and is just a defective item that is out of warranty for the 1-year replacement warranty, and refuses to cover this repair under the battery warranty where the Power Conversion System is located. Service center states there is nothing the customer did wrong or could do to cause this problem, acknowleges it is a defective part, and insists it is customer pay with no indication of an updated part. What happens when the Power Conversion System fails is the car is stranded and cannot recharge or operate its safety systems. This should be a recall item if it was updated to a newer part correcting defective design. …
For a growing number of Model 3 owners, components in the HV Battery Service Panel are breaking down, yet Tesla refuses to cover the repair under its Battery and Drive Unit Warranty. Specifically, the "power conversion system" (PCS) in that panel is failing, and reducing an AC charge from 48A to 32A to 16A to... zero. If an owner drives to a location to charge from a Level 1 or Level 2 charger, and the PCS has failed, that owner will be stranded, unable to operate the vehicle. I have submitted a request for mediation to the American Arbitration Association (case no. 01-22-0001-9026), but I deem it important to not only address the problem in my vehicle, but all the others experiencing this same breakdown. I am thus reporting it to NHTSA, as I purport that a recall is in order. …
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 (380k , far below Tesla's 1,000k 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. …
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. …
My car was parked and was charging in our garage when it suddenly shut off. I got into the car to get something, but noticed the car's computer screen did not light up. I tried to open the glove box and it also would not open. When I tried to open the car door button, it also would not open the door while I was still inside. I got out of the car using the manual car handle and realized the charger would not unplug from the car either. I was very scared that the car was going to burn because the battery was charging at the time and everything suddenly happened. In addition, the backseat doors do not have a manual car handle to open the door. In an event of an emergency and the power shuts off, how are passengers sitting in the backseat going to escape from the vehicle??? The cause was due to a 12v battery malfunction.
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.
PCS Charger (Onboard) is failing on numerous early build Model 3 cars (2017-2019). Telsa is claiming that this is not included in battery warranty, however Tesla's own service manual shows this part specifically in the HV Battery System. I still have the fault PCS charger in the car, it is limited to 32Amps but several forums and webpages state its only a matter of time before I am limited to 16Amps The car is unable to charge at a reasonable recovery rate in which you can even use the vehicle for it's intended purchase. Tesla has acknowledge it's failure but is unable to produce actual number of failed units. The warning lamp had been displaying "dirty electrical grid" for quite some time until I was able to search the internet for the exact issue.
On December 27, 2022, in light evening street traffic, my car accelerated briefly without the accelerator pedal being applied. I took my foot off the accelerator pedal to decelerate for an upcoming red light. While my foot was off the pedal, the car accelerated and lurched forward. The car was towed to the Tesla Sacramento Service Center. The technician incorrectly cited the "creep mode" as being involved. The car was in motion when it unexpectedly accelerated. "Creep Mode" only engages when the car is close to or fully stopped. Tesla technician was unable to determine an accurate reason for the unexpected acceleration.
My Tesla Model 3 without any warning stopped working suddenly. I could not put the car in drive and there were error messages about climate control and electrical system. I had to get the car towed to the service center as it was blocking my other car in the driveway. The service center in Sunnyvale, CA diagnosed the problem to be a faulty PTC heater and has charged me over $1100 to replace it. I beileve it is quite absurd to have a fault in the HVAC system render the whole vehicle completely immobile and useless. This seems like a serious design flaw and it could lead to serious health or safety concerns.
Fuel System complaints in other Model 3 years
Frequently asked questions
How common are fuel system problems on the 2018 Tesla Model 3?
NHTSA has 24 complaints about the fuel & propulsion system of the 2018 Tesla Model 3, 2% of the model year's 1,032 complaints.
Is there a recall for 2018 Tesla Model 3 fuel system problems?
No. NHTSA lists no fuel & propulsion system recall for the 2018 Tesla Model 3, though it has 19 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2018 Tesla Model 3 fuel system problems start?
Half of the complaints with a recorded mileage happened before about 13,000 miles, and 100% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 1 fire and 0 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.