2021-2022 BMW X3 / X5 / X6 / X7 Coolant Level Warning

Symptoms

Owners of certain 2021-2022 BMW X3, X5, X6, and X7 vehicles may observe a specific Check Control message appearing on their dashboard. The message displayed is: "Top up coolant."

This warning appears despite the engine being cold and the coolant level not actually being below the minimum required level. The presence of this false warning can be confusing and lead to unnecessary concern for drivers.

Diagnosis and Trigger Conditions

The primary condition for this issue is the appearance of the Check Control message "Top up coolant." (ID 166) when the engine is cold and the actual coolant level is not low. This indicates a diagnostic error rather than an actual mechanical problem with the coolant system.

The system incorrectly interprets the coolant level, triggering the warning even when the fluid is at an appropriate level. This is a software-related anomaly rather than a physical leak or a faulty sensor.

Repair Procedure Summary

The resolution for the false "Top up coolant." message involves a diagnostic software update. This update aims to correct the erroneous coolant level detection logic within the vehicle's control system.

Technicians will connect the vehicle to a diagnostic system to apply the necessary software patch. This procedure recalibrates the system to accurately read coolant levels, preventing the false warning from appearing.

Owner Action

If you own a 2021-2022 BMW X3, X5, X6, or X7 and are experiencing the "Top up coolant." message when you know your coolant level is adequate, it is recommended to contact your authorized BMW dealer.

Inform them about the persistent Check Control message (ID 166) and the conditions under which it appears. Your dealer can perform the necessary diagnostic update to resolve this software issue.

Source: NHTSA ID 10215751