Test R

PINPOINT TEST R: LFC 21/DTC B1921 - RCM BRACKET GROUND RESISTANCE HIGH

Test R1:

Test R2-R4:

Test R5-R6:

Test R6-R7:

Normal Operation

WARNING: The tightening torque of the restraints control module (RCM) retaining bolts is critical for proper 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 may set the LFC

The restraints control module (RCM) monitors the resistance between the ground connections at its housing and the reference ground at pin 21. If the RCM detects a difference in resistance, 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 RCM housing ground and pin ground can be caused by:
- incorrect seating of the RCM retaining bolts.
- incorrect tightening torque of the RCM retaining bolts.
- high resistance on RCM logic ground circuit 91-JA14 (BN/GN).
- a faulted RCM.