2021 BMW Active Cruise Control Unexpected Deceleration

Owners of certain 2021 BMW models, including the 2021 BMW 330i, may experience an issue where their vehicle unexpectedly decelerates while using the Active Cruise Control (ACC) system. This condition specifically occurs when the "Active Cruise Control with Stop & Go (ACC) function is activated."

This manufacturer communication, identified by NHTSA ID 10184592, highlights that the vehicle may slow down without warning, which can be a concern for drivers relying on the ACC system for maintaining speed and distance.

Symptoms

The primary symptom reported is "Vehicle slows down (decelerates) unexpectedly while Active Cruise Control with Stop & Go (ACC) function is activated." This means that even when the ACC system is engaged and set to a specific speed, the vehicle may suddenly reduce its speed without driver input or an apparent reason related to traffic conditions.

What Owners Should Know

BMW has issued a manufacturer communication (NHTSA ID 10184592) to address this specific concern related to the VEHICLE SPEED CONTROL:CRUISE CONTROL system. This communication serves to inform dealerships about the potential for unexpected deceleration when the Active Cruise Control with Stop & Go (ACC) function is active. While the document does not detail a specific repair procedure or recall, it acknowledges the existence of this operational anomaly.

This communication applies to various 2021 BMW models, not just the 2021 BMW 330i. If you own one of the affected vehicles and experience this issue, it's important to be aware that BMW has recognized the problem.

Next Steps

If your 2021 BMW experiences unexpected deceleration while the Active Cruise Control with Stop & Go (ACC) function is activated, it is recommended to contact your authorized BMW dealership. They can investigate the issue further, check for any available software updates, or perform diagnostics related to the VEHICLE SPEED CONTROL:CRUISE CONTROL system. Be sure to mention the specific symptom of unexpected deceleration with ACC activated.

Source: NHTSA ID 10184592