2017 Tesla Model S transmission problems

Filed Oct 8, 2026 · Engine, Transmission · MO

I am reporting a suspected defect in the rear Large Drive Unit (LDU) of my vehicle, a 2017 Tesla Model S P100D with approximately 40,815 miles. The component involved is the rear drive unit’s rotor seal, which is known to allow engine coolant to leak into the motor. The concern is safety-related. Tesla coolant is electrically conductive and can form a conduction path inside the motor and inverter, and coolant can also damage bearings. Once coolant enters the drive unit, the result can be electrical faults, loss of drive power. If the drive unit fails while the vehicle is moving, especially at highway speeds, it could cause a sudden loss of propulsion or reduced braking-related regeneration, which could lead to a crash. Other owners have reported this kind of failure without warning. I am concerned about both the loss of propulsion and the electrical hazard of coolant in high-voltage components. I have not had a drive unit failure. I have received a quote of approximately $1,500 from an independent shop to apply a preventive coolant bypass in which I am not confident that an aftermarket bypass will fully prevent the failure, and I have not seen independent long-term data on its results. I have was told that a drive unit replacement, if the leak progresses, could cost $5,000 or more. A Tesla service advisor told me on earlier in 2026 when they inspected my Tesla that Tesla will only address this issue if the drive unit has already failed, and that there is no preventive repair available for vehicles that have not failed. I believe this is a design defect in the rear Large Drive Unit. Tesla has replaced failed units under warranty with a revised “U” drive unit that blocks coolant from entering the rotor. I request that the federal safety agency investigate whether the original rotor seal design is a safety defect and whether the revised design should be offered to owners of affected vehicles, including those whose drive units have not yet failed.

Filed Nov 28, 2025 · Electrical, Fuel system · CA

This is a supplemental filing to my prior the federal safety agency complaint (#11697718) regarding a high-voltage isolation fault and shutdown risk. The vehicle displayed warnings including “vehicle may shut down during driving,” “may not charge,” and repeated BMS isolation fault messages. It became inoperable at a public charging station. The manufacturer confirmed isolation faults in the drive unit and the A/C compressor. Their own service notes stated that the vehicle “may shut down during regular driving” and that charging “may not be safe.” Despite this, the vehicle was left at 0% state of charge for an extended period and then charged by the manufacturer. They later stated to a regulator that the vehicle was “trickle charged at 1 amp for 6 hours,” but the vehicle’s range increased by approximately 100 miles, which is not physically possible at that charging current (1 amp at 240V for 6 hours = 1.44 kWh ≈ 4–5 miles). This discrepancy suggests the vehicle may have been charged at a higher rate than claimed and without proper cooling, despite the documented A/C failure that is necessary for battery thermal management. Battery condition is unknown because the manufacturer refused to perform or provide a battery health analysis, isolation resistance values, thermal logs, or charging session data. The safety defect could not be verified as repaired. While this safety issue remained unresolved, the manufacturer rejected a Tesla roadside tow arranged under regulator instruction to second service center and instead arranged an unauthorized tow to remove the vehicle from their facility without my consent. The vehicle was taken to a non-manufacturer storage lot while still in an unsafe state. I am concerned about: • high-voltage isolation faults, • shutdown risk during driving, • unsafe charging performed by the manufacturer, • possible battery damage from low SOC and charging without A/C cooling, and • mishandling of an active safety defect. The vehicle is available for inspection.

Filed Nov 13, 2025 · Electrical, Engine · CA

This is an update to the federal safety agency Complaint #XXX with new safety information. My 2017 Tesla Model S (VIN [XXX] ) has a confirmed high-voltage isolation fault. Tesla replaced the rear drive unit under warranty, but Tesla’s own technician notes now state: “There is a risk of isolation alerts reoccurring during regular driving, use of HVAC system, or DC charging.” “Vehicle may power off due to isolation faults when the air conditioning is used.” This is Tesla acknowledging in writing that the vehicle may shut off during normal driving, even after repair. This presents a serious crash risk. The original failure occurred during Supercharging, with warnings including: • “Electrical system power reduced — vehicle may shut down unexpectedly” • “Vehicle may not restart” • “Air conditioning reduced — DC charging reduced” Tesla reproduced the isolation fault during diagnosis. Even after replacing the rear drive unit, Tesla documented that the isolation defect still exists and prevents a battery health check or DC fast-charge validation. Tesla has attempted to return the vehicle to me in this unsafe condition, while admitting the defect persists. They also stated they may charge storage fees or tow the vehicle, despite the unresolved safety issue. The defect affects the HV bus and can cause loss of propulsion, shutdown during driving, and charging failure. Tesla has not provided numeric test results (megohm isolation readings, insulation tests, or validation data) proving the vehicle is safe. This is an ongoing, manufacturer-confirmed HV isolation defect that can lead to sudden power loss. I request the federal safety agency review Tesla’s handling of this issue and link this filing to Case #XXX. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 2, 2023 · Brakes, Transmission · 54,000 miles · CA · crash

The contact owns a 2017 Tesla Model S. The contact stated while approaching a stop light, while the contact was depressing on the brake pedal to slow down the vehicle accelerated on its own causing the contact to strike the vehicle in front. The contact stated that no warning light illuminated, and the brake assist did not activate. The contact stated when the vehicle struck the vehicle in front the vehicle continued driving forward and then the vehicle was able to come to a complete stop. The vehicle had front-ended damages and the other vehicle had rear-ended damages. No one was injured. The air bags deployed. A police report was not filed. The vehicle was towed to a repair center. The vehicle was not diagnosed. The manufacturer was contacted and did not provide any assistance. The failure mileage was 54,000.

Filed Oct 26, 2022 · Suspension, Transmission · PA

While reversing into a parking spot, like I have over 1000 times in this car, I heard a loud crack and scrape. When the tow driver got the car up we were able to see it was a Lower A-arm failure in outward loaded bearing stress. This seems like a common problem with these cars as a simple google search found many other drivers with similar issues.

Filed Feb 5, 2020 · Acceleration, Electrical · 35,000 miles · CA · crash · 2 injuries

I have reached out to tesla 3 times to fix a sudden unintended acceleration issue. 11 days after I reported the issue and they told me my car was ok to drive I got into a accident. It took tesla 5 months to give back the reports of the crash in which they said it was my fault. I have lost trust in the company and have seen that 127 other people have been affected by the same issue according to cnn please take care of this issue. Any tesla owner is a pioneer of a future creation. After the accident they told me autopilot is on beta mode its not perfect yet. They should not allow public to use a hazardous software. Also tesla employees were very negligent. I almost died in this accident with my father and the manager had no idea of my case even after my car was given to me and they said it was ok to drive. I got into a accident 11 days after they ok'd my car please help as I am frustrated and do not know what to do anymore or who to get to fix my car. I have documentation of addressing sudden intended acceleration to tesla multiple times. Thank you

Filed May 15, 2019 · Electrical, Fuel system · 9,000 miles · CA

On saturday 5/11/2019 around 12:45pm while I was driving on the highway the car suddenly made a loud sound then the car shut down in the middle of the highway leaving me stuck. The car would not go into gear. The car display an error on the center console "unable to drive, please proceed to safety" (something like this) I did not take a photo since I was concerned about being rear ended. I had to call 911 to stop all traffic so the car could be pushed off the highway. As we were about to push the car it started working again. I will be taking the car into tesla service so they can try to determine why this occurred. This could have caused a major accident to myself and others if this happened during non rush hour traffic.

Filed Dec 21, 2018 · Acceleration, Transmission · 12,000 miles · NV · crash

Our tesla has had two incidents in the last three months of uncontrollable acceleration....once slowly going into a parking place and once backing out of our garage. The first one resulted in a couple of cracked ribs (with seatbelt on) and $18,000 in damage. The second incident: the tesla, when backing up went totally out of control by accelerating and it barreled across the street and knocking down a tree before coming to a stop. The tesla is now in the repair shop with extensive damage to the rear of the car. Not sure yet of the dollar amount. I feel this is a serious defect in the tesla model s.

Filed Mar 15, 2018 · Fuel system, Suspension · 5,000 miles · CA · crash

Here is a tesla in the junkyard: https://www.copart.com/lot/22469458 the suspension has colllollopsed. The front wheels are all brutalised! All the damage appears to be self inflicted after the suspension went whompy. Please investigate. Thank you. Concerned senior citizen. Etc etc.

Filed Jul 17, 2017 · Acceleration, Steering · 600 miles · CA

On july 13, 2017, my tesla was driving south on the I-680 in the vicinity of fremont, california. My vehicle was in self-drive mode traveling in the left-most lane at 65 MPH. My hands were on the steering wheel. We entered a long curve to the right and approached stopped cars ahead of us. The self-drive mode in my tesla then stopped operating and I was left to suddenly have to steer the tesla onto the left shoulder of the highway in order to avoid hitting the vehicle directly ahead of me. This all occurred under clear skies and dry road conditions. I could not simply accept this behavior by my vehicle without registering a complaint at my tesla dealer in seaside, california. The tesla service rep examined the logs on my vehicle and later that same day reported to me that the self-driving feature on my tesla was still in beta stage and that my new tesla's firmware was defective. I would now like tesla to take back this tesla and return to me a full refund. This is the second major failing of this tesla which has only about 700 miles on its odometer. I took initial delivery of this tesla on may 3, 2017. This failure of the self-driving feature occurred at around 10:30am on july 13, 2017. The first failure of the navigation system occurred on may 3, 2017, the original delivery date. The navigation system had simply frozen at the dealership. Again, I would like to return this vehicle to tesla for a full refund.