Normal Operation
WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
The restraints control module (RCM) continuously monitors the resistance between the ground connections at the mounting bolts and the reference ground at C2041a pin 16, circuit 1203 (BK/LB). If the RCM detects a difference in resistance, it will store DTC B1921 in memory and flash lamp fault code (LFC) 14 on the air bag warning indicator.
- DTC B1921 Air Bag Diagnostic Monitor Ground Circuit Open - If the RCM detects a resistance difference between the case ground and pin 16 of C2041a, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RCM mounting
- RCM