Brake warning lamp
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Volvo V70, 2006 Volvo V70, 2005 Volvo V70, 2004 Volvo V70, and 2003 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
The brake control module (4/16) (called ABS module on model years up to and including 2001) informs the driver information module (5/1) via the Control area network (CAN) if there is a fault in the brake system. The driver information module indicates this to the driver by lighting the red general warning lamp and displaying a text message.
The brake fluid level sensor detects the level of the brake fluid in the reservoir. When the level is low, a switch in the sensor closes and the warning lamp lights. This function is directly connected to the driver information module.