Control unit: Indicators
WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
The indicator is in the gauge control module:
The low tire pressure/TPMS indicator comes on when any tire pressure is low.
The low tire pressure/TPMS indicator blinks when the system is malfunctioning.
Courtesy of AMERICAN HONDA MOTOR CO., INC.