I am writing to file a complaint regarding my 2023 Toyota GR Corolla Circuit Edition. The issue pertains to the ECU programming, which was not properly calibrated for the wheels that came with this model. Instead, the weight and dimensions from the Morizo Edition were utilized. This discrepancy causes the vehicle to inaccurately register speed, which is a significant safety concern. The malfunctioning component is the ECU, and it is available for inspection upon request. The inaccurate speedometer readings put my safety and the safety of others at risk by potentially causing unintentional speeding, which could lead to traffic violations and increased risk of accidents. Additionally, the inaccurate speed readings can affect other vehicle systems, such as collision alerts, adaptive cruise control, and braking systems, which rely on accurate speed data to function correctly. For example, collision alerts may not activate in time, adaptive cruise control may not maintain safe distances, and braking systems may not respond appropriately to speed changes. Furthermore, the driver display includes a light that indicates when the vehicle is exceeding the detected speed limit for the current area, which is rendered unreliable due to the inaccurate speedometer. Additionally, the console only displays speed in kilometers per hour (km/h) with no option to switch to miles per hour (mph), which is problematic for North American vehicles and other countries that use mph. The low fuel light also comes on with 20 miles left, which could be related to the same calibration issue affecting the speedometer and other systems. The problem has been reproduced and confirmed by an independent service center. However, the vehicle has not yet been inspected by the manufacturer, police, or insurance representatives. There were no warning lamps or messages indicating the problem prior to the failure, and the issue was first noticed shortly after taking delivery of the vehicle.

- Wamego, KS, USA