2021 BMW 330i Sunroof Reverses When Closing TSB

Owners of certain 2021 BMW 330i, M340i, and 330e vehicles may encounter an issue where the sunroof reverses direction when closing. This behavior, described as the sunroof "anti-trapping" just as the glass makes contact with the wind deflector, can lead to the sunroof not initializing correctly.

Symptoms

The primary symptom is the sunroof reversing direction just before it fully closes. Specifically, the sunroof glass meets the wind deflector, and instead of completing the closing cycle, it reverses. This can result in the sunroof failing to properly initialize, which may affect its normal operation.

Diagnosis / Trigger Conditions

This issue, where the 2021 BMW 330i sunroof reverses when closing, is specifically triggered by the interaction between the sunroof glass and the wind deflector during the closing sequence. The system's anti-trap function is activated, causing the reversal. Technicians would likely observe this behavior to confirm the condition.

Repair Procedure Summary

While the specific repair steps are not detailed in this manufacturer communication, issues like the "sunroof reverses when closing" often point to a need for software updates or recalibration of the sunroof system. A BMW service technician would diagnose the exact cause and perform the necessary adjustments or programming to resolve the anti-trap activation and ensure proper sunroof initialization.

Owner Action

If you own a 2021 BMW 330i, M340i, or 330e and experience your sunroof reversing when closing, it is recommended to contact your authorized BMW dealership. Explain the symptom, specifically mentioning that the sunroof reverses when the glass meets the wind deflector. The dealership can perform diagnostics and apply any necessary software updates or repairs under this manufacturer communication (TSB).

Source: NHTSA ID: 10188947