Yellow Parking Brake Indicator
WARNING: This page is about a different car, the 2013 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
The yellow parking brake indicator is used in conjunction with the message center to notify the driver of parking brake system concerns. When a concern or DTC is present, the indicator illuminates and a message is displayed in the message center. The yellow parking brake indicator also illuminates when the parking brake system is in service mode.
Refer to: INSTRUMENT PANEL CLUSTER (IPC) - SYSTEM OPERATION AND COMPONENT DESCRIPTION .