NHTSA complaint #11759336

Owner complaint summary

My 2025 Acura MDX suffers from a severe safety defect regarding the Auto Idle Stop (auto start-stop) system. When the vehicle comes to a complete stop at intersections or traffic lights, the engine shuts off as intended. However, upon releasing the brake pedal to accelerate, the engine completely fails to auto-restart.Instead of restarting, the vehicle drops out of the auto-restart sequence entirely, shifts itself out of drive, and displays a critical safety message on the dashboard: "To start engine: Brake + Push".This completely strands the vehicle in live traffic, forcing me to manually shift into Park, press the foot brake, and push the engine start button while traffic accumulates behind me. This creates an immediate rear-end collision hazard.The dealership has already attempted to diagnose and repair this issue under warranty by replacing both the vehicle's battery. This hardware replacement did not fix the problem; the failure continues to occur unpredictably less than a week (and 25 miles) after replacement. The root cause appears to be a software, Powertrain Control Module (PCM), or sensor tracking defect where the vehicle fails to recognize it is in an automated restart sequence.I am filing this complaint to be officially included in the ongoing NHTSA Engineering Analysis EA25004 regarding Honda/Acura Auto Idle Stop failures, as the current hardware recall remedies are entirely ineffective for the 2025 model year.