NHTSA complaint #11715908

Owner complaint summary

On November 26, 2025, while traveling in stop-and-go freeway traffic, I experienced a severe braking failure that led to a rear-end collision. Despite applying maximum force to the brake pedal, the vehicle did not decelerate as expected. Objective technical evidence from the Bosch CDR report (Case #1105768) confirms a critical system failure: Extreme Driver Input: At -0.5 seconds before impact, Driver Applied Brake Pedal Pressure reached 10,935 kPa, representing a near-maximum emergency braking effort. Inadequate Response: Despite this peak pressure, the Vehicle Indicated Speed decreased only from 24 MPH to 22 MPH in the final 0.5-second interval. Data Discrepancy: The vehicle decelerated by 12 MPH (from 36 to 24 MPH) between -1.0s and -0.5s under lower pressure (7,695 kPa). However, when brake pressure was increased to its peak at -0.5s, deceleration effectively stalled. Electronic Anomaly: The Traction Control System (TCS) was reported as "Active" throughout the braking event, indicating potential improper electronic intervention. This vehicle has a history of significant electrical failures, including a total power loss on 10/15/2024 that required a high-voltage battery replacement. The failure of the braking system to respond to maximum driver input poses a catastrophic safety risk. I am requesting an investigation into the 2024 Cadillac LYRIQ's brake-by-wire and electronic stability control integration.