Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The restraints control module (RCM) checks the HS-CAN circuits for faults. If the RCM detects a fault on the HS-CAN circuits, it will store diagnostic trouble code (DTC) U0073 in memory and illuminate the air bag indicator.