2017 Tesla Model S Engine Problems

This is an update to NHTSA 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 NHTSA 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)