2018 Tesla Model 3: sudden loss of power

Filed Sep 6, 2026 · Acceleration, Electrical · AL

While my wife was driving, the high-voltage battery failed and the car went into reduced power/limp mode. Tesla later determined that coolant had gotten into the high-voltage battery and caused it to fail. My main concern is that we had no warning that there was a coolant leak or that coolant was getting into the battery. There was no low-coolant warning or anything telling my wife that there was a serious problem developing. By the time the car started giving high-voltage and reduced-power warnings, the damage had already occurred and Tesla said the battery needed to be replaced. What concerns me even more was what happened after Tesla received the car. Tesla removed the battery and quarantined it in the parking lot. They told us in writing that it was removed because of coolant ingress as a safety precaution and that a specialized technician had to determine whether the battery was safe to discharge. During a phone call, a Tesla employee also told me they quarantined it because there was a possibility the battery could explode and they did not want anyone injured or anything damaged if that happened. That was alarming because my wife had just been driving this car, and afterward it sat in our driveway while we waited for it to be taken to Tesla. At no point were we told that the battery could be dangerous or that the vehicle should be kept away from people or property. We had no idea Tesla would consider the condition serious enough to quarantine the battery once they received it. Tesla later confirmed in writing that coolant ingress was the root cause of the battery failure. I would like the federal safety agency to look into why this condition was able to get this far without warning the driver and whether other vehicles could have the same issue.

Filed May 3, 2026 · Driver assistance · CA

Safety Issue: Defective interior cabin camera causes Tesla Full Self-Driving (FSD) to disengage abruptly and without adequate warning at freeway speeds. I am a [XXX] driver. I purchased FSD capability with this vehicle in December 2018. In October 2025, I had the FSD hardware upgrade (HW2.5 to HW3) installed at Tesla's Encinitas, CA service center (B.A.R. License [XXX] ). Within days, FSD would became completely unusable due to a recurring "Cabin camera unavailable — schedule service" alert that instantly disengages the system. The disengagement occurs on the freeway at highway speed, without meaningful advance warning. As a [XXX] driver, the sudden loud alarm and loss of assisted driving is genuinely alarming — it is not immediately clear in the moment whether the vehicle has lost power or experienced a critical failure. This is exactly the kind of dangerous situation driver assistance systems should prevent, not cause. Tesla's own diagnostic confirmed the defect (Diagnostic Invoice No. XXX, November 27, 2025, Encinitas service center): "Cabin camera unavailable" alert verified Intermittent stream exit faults detected in the selfie/cabin camera Low-voltage circuit and wiring checks were normal — ruling out wiring Conclusion: fault is within the camera module itself; technician recommended replacement The defect is FSD-specific. The cabin camera works correctly for Sentry Mode, live security viewing, and all normal driving. It fails exclusively when FSD is engaged and demands sustained driver monitoring. The camera housing also becomes extremely hot to the touch during FSD use, consistent with reports from other 2018 Model 3 owners describing identical symptoms after their HW3 retrofits. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 3, 2025 · Electrical, Fuel system · PA

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.

Filed Apr 3, 2025 · Electrical, Fuel system · PA

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.

Filed Apr 19, 2024 · Body, Locks · WA

The 2018 Tesla model 3 has no manual release for rear passenger doors. Rear doors often fail to open due to door panel alignment or actuator for door. Doors will feel like they are opening but will be stuck. passenger will be unable to exit the rear of the vehicle incase of fire, power loss or due to an accident with no ability to exit the rear of the vehicle.

Filed Jan 9, 2024 · Steering · WA

Lost power steering. It started working again, but the dealership recommended a replacement due to corrosion which amounted to around 4k. Comprehensive insurance would not cover since the damage was gradual and not immediate.

Filed Mar 29, 2023 · Electrical · TX

The power conversion system is failing on my vehicle. It is causing faults that trip the breakers at my charger and could potentially cause a major problem at my charging station. It could also cause my vehicle to be stranded or possibly lose power while driving.