Functional description

The brake fluid level switch detects a drop below the required brake fluid level in the brake fluid expansion tank.

The DSC control unit sends the signal of the bus system to the instrument panel. The instrument panel issues a Check Control message. The usual motion of the brake fluid within the reservoir does not generally trigger a Check Control message.

The brake fluid level switch contains a reed contact. The reed contact is closed when the brake fluid level is between the maximum (MAX) and the minimum (MIN). The reed contact opens when the brake fluid level is below the minimum (MIN).

Courtesy of BMW OF NORTH AMERICA, INC.

Short circuit or line disconnection cannot be detected on the brake fluid level switch. A line disconnection is interpreted as a brake fluid loss. A short circuit is not detected.