B1921

LFC 21 / DTC B1921 (Steps 1 - 5):

LFC 21 / DTC B1921 (Steps 6 And 7):

Normal Operation

WARNING: The tightening torque of the air bag diagnostic monitor retaining bolts is critical for proper air bag system operation. Refer to AIR BAG DIAGNOSTIC MONITOR REMOVAL/INSTALLATION for proper torque values.

The air bag diagnostic monitor monitors the resistance between the ground connections at its housing and the reference ground at pin 21. If the air bag diagnostic monitor detects a resistance greater than 100 ohms, it will store a diagnostic trouble code (DTC) B1921 in memory and flash a lamp fault code (LFC) 21 (or higher priority code if one exists) on the air bag indicator.

Possible Causes
High resistance between the air bag diagnostic monitor housing ground and pin ground could be caused by:
- improper seating of the air bag diagnostic monitor retaining bolts.
- improper tightening torque of the air bag diagnostic monitor retaining bolts.
- high resistance on both air bag diagnostic monitor logic ground (B/O) wires.