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Electrical System
04/23/2026
I own a 2020 Porsche Taycan 4S (in service Nov 2, 2020) with a performance+ HV battery. I am currently facing a third round of module replacements. The service chronology and detail is set forth in the attached e-mail I sent to Porsche and the attached service reports. The safety concern I have is that when the defective modules fail, the vehicle suddenly becomes inoperable. The last failure incident in April 2026 resulted in the vehicle blocking in two other vehicles until it could be removed on a flatbed. I simply do not feel safe driving a vehicle that could shut down whenever the next module failure happens. There are 33 modules in the HV battery. 15 have been replaced already and it is clearly an ongoing issue as the vehicle is currently in service for a third round of module replacement after the vehicle shut down only 4 months and less than 2,000 driving miles after the previous module replacement. As a result of my increasing safety concerns, I requested Porsche replace...
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Steering, electrical System, vehicle Speed Control
05/12/2026
While driving my Porsche Taycan through a high-speed intersection, the vehicle suddenly displayed battery and chassis system error messages instructing me to pull over immediately. Before I could safely move the vehicle to the side of the road, it completely lost propulsion, speed control, and steering capability, causing the vehicle to abruptly slow to 0 mph in active traffic and leaving me stranded in the middle of the roadway. This created an immediate safety hazard, as approaching vehicles nearly collided with my car because it effectively performed an unexpected emergency stop without warning. Approximately one month earlier, the vehicle experienced the exact same failure while parked, displaying battery and chassis errors and losing power and steering functionality. The vehicle was towed to an authorized Porsche dealership, where it remained for approximately one month; however, the dealer was unable to diagnose the problem and returned the vehicle to me, stating that no fault co...
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Tires
06/08/2026
I have had two delaminations of my tires, one in August 2023, and one just this week - June 2026. Pictures are attached. Both tires had more than 50% tread left, and the tread was delaminating from the sidewall. MICHELIN PILOT SPORT 4S Max Performance Summer Tires in 285/40ZR22
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Service Brakes, forward Collision Avoidance
04/29/2026
My 2020 Porsche Taycan 4S (VIN [XXX]) has a recurring, dangerous brake failure that remains unresolved after multiple dealer repair attempts. At low speed, the automatic emergency braking system activates on its own and begins decelerating the car. As the car slows to roughly 5 mph, the brake pedal drops, braking pressure disappears, and the vehicle keeps rolling forward. Pressing the pedal as hard as I physically can does not bring the car to a stop. On more than 5 occasions I have had to steer around the vehicle in front of me to avoid a collision. The failure is intermittent and unpredictable, which makes it especially hazardous. The problem has existed since early in my ownership. On [XXX] (16,631 miles), Porsche Livermore found multiple brake booster faults and replaced the brake booster assembly, re-bled the brakes, and recoded the PSM control unit (RO [XXX]). The dead-pedal emergency-stop failure continued. I returned on [XXX] (40,904 miles) for the same problem; the dealer reco...
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Power Train, engine, fuel/propulsion System
01/15/2025
Component/system: High-voltage (HV) battery system and power electronics. 2020 Porsche Taycan Turbo, VIN [XXX] . Vehicle available for inspection. Safety risk: Since January 2025, the vehicle has repeatedly displayed a "pull over and park safely" emergency warning and shut off unexpectedly while driving at highway and surface road speeds. Sudden loss of propulsion at speed created serious collision risk. Dealer-confirmed: Porsche Woodland Hills documented (July 2025): "vehicle just shut off on him as he was driving — multiple occurrences." A second shutdown was confirmed August 2025: "vehicle shut off while driving — high voltage battery error." Four or more repair visits under my ownership for this same defect. Fault codes confirmed by authorized Porsche dealers: P0AA600 (HV Battery Voltage System Isolation Fault — highest severity), P0A4000 (Rotor Position Sensor Fault), U178800 (Front Axle Power Electronics Drive Fault), P061B00 (Torque Calculation Fault). November 2025: Porsche...