Normal Operation
WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
The tightening torque of the restraints control module (RCM) retaining bolts is critical for correct air bag supplemental restraint system (SRS) operation. REFER to RESTRAINTS CONTROL MODULE (RCM) for correct torque values.
NOTE:
A resistance difference as low as 10 ohms can set the LFC.
The restraints control module (RCM) monitors the resistance between the ground connections at the mounting bracket and the reference ground at C310a pin 16, circuit 649 (BK/OG). If the RCM detects a difference in resistance, it will store diagnostic trouble code (DTC) B1921 in memory and flash lamp fault code (LFC) 14 (or higher priority code if one exists) on the air bag indicator.