Test H: B1921 - Air Bag Diagnostic Monitor Ground Circuit Open

PINPOINT TEST H: B1921 - AIR BAG DIAGNOSTIC MONITOR GROUND CIRCUIT OPEN

Lamp Fault Codes (LFCs)
The following LFC indicates the specific fault associated with DTC B1921:







WARNING: Always tighten the fasteners of the restraints control module (RCM) and impact sensor (if equipped) to the specified torque. Failure to do so may result in incorrect restraint system operation, which increases the risk of personal injury or death in a crash.

NOTE: A resistance difference as low as 10 ohms may set the LFC.

Normal Operation
The restraints control module (RCM) monitors the resistance between the ground connections at the mounting bracket and the reference ground at the C310a Pin 16, circuit 676 (PK/OG).

If the RCM detects a difference in resistance, it will store DTC B1921 in memory, flash LFC 1-4 on the air bag warning indicator.

- DTC B1921 Air Bag Diagnostic Monitor Ground Circuit Open - If the RCM detects a difference in resistance between the ground circuit and the RCM mounting ground, it will set this DTC.

This pinpoint test is intended to diagnose the following:
- RCM bracket not securely mounted
- Wiring, terminals or connectors
- RCM

H1-H3:

H4-H6:

H7: