NHTSA Complaint #11717870 — 2022 TESLA MODEL 3

RECURRING 12V LOW-VOLTAGE SYSTEM FAILURE AND DEFECTIVE REAR DEFROSTER HEATER GRID VEHICLE: 2022 Tesla Model 3 (VIN: [XXX] ). ODOMETER: 114,093 miles at time of third service visit. SUMMARY OF DEFECT: Vehicle has experienced recurring low-voltage (12V) system alerts since late December 2025. The 12V battery has been replaced three times by Tesla service. After each replacement, the low-voltage alerts return within days. Tesla's diagnostic system detected a DCR (DC resistance) reading of 16.8 milliohms against a threshold of 16 milliohms, indicating the battery's internal resistance is too high for the vehicle's electrical system to function properly. A brand-new 12V battery showed "Degraded - Replace" status within one week of installation. These low-voltage errors did not exist before Tesla replaced the 12V battery during the first service visit. DIAGNOSTIC FINDINGS: During the third service visit (February 2026), Tesla technician performed a resistance check on the rear defroster heater grid and described it as "out of spec but not significantly." Ground straps were also described as "out of spec but again not significantly." The technician stated there was "no smoking gun yet" and it was "maybe a combination of all leading to the 12V warning." Tesla proposed replacing the rear backlight glass at a cost of $1,265 to the customer. Additionally, severe rodent damage was discovered in the front wiring harness with chewed wires and nesting material. Despite this confirmed damage to the electrical system, the service manager stated the rodent damage was "not associated with the error" while the technician simultaneously stated there was no confirmed root cause. SAFETY CONCERN: The recurring 12V low-voltage condition presents a safety risk. The 12V system powers critical vehicle functions including exterior lighting, hazard lights, door locks, windows, the vehicle's computer systems, and safety features. Repeated system alerts include DIF_a018_hwLVSupplyUV (ha INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATIO