Test M

PINPOINT TEST M: LFC 14/B1921 - AIR BAG DIAGNOSTIC MONITOR GROUND CIRCUIT OPEN

Test M1:

Test M2-M4:

Test M4-M5:

Test M6-M7:

Normal Operation

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 may 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 1203 (BK/LB).

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.

Possible Causes
A resistance difference between the RCM bracket ground and harness ground can be caused by:
- RCM bracket not securely mounted.
- faulted wiring, terminals, or connectors.
- a faulted RCM.