Driver-Side Air Bag Circuit Shorted to Ground

Pinpoint Test 17: LFC 36/DTC B1993 - DRIVER-SIDE AIR BAG CIRCUIT SHORTED TO GROUND

Normal Operation
The restraints control module (RCM) monitors the resistance to ground at RCM S-2041a and S-2041b, pins 2 and 3. If the resistance is less than 1000 Ohms at either pin, the RCM will interpret that as a ground short, store diagnostic trouble code (DTC) B1993 and flash lamp fault code (LFC) 36.

Possible Causes
A driver-side air bag circuit short to ground can be caused by:
- grounded wiring on circuit (W/LB).
- damaged wiring on circuit (BR/LB).
- ground short in the driver-side air bag module.
- an RCM internal concern.

WARNING: If the supplemental restraint system (SRS) is being serviced, the system must be deactivated and restraint system diagnostic tools must be installed.

The air bag restraint system diagnostic tools must be removed and the air bag modules reconnected when the system is reactivated to avoid non-deployment in a collision, resulting in possible personal injury.

NOTE: Diagnostics or repairs are not to be performed on a seat equipped with a seat side air bag with the seat in the vehicle. Prior to attempting to diagnose or repair a seat concern when equipped with a seat side air bag, the seat must be removed from the vehicle and the restraint system diagnostic tools must be installed in the seat side air bag electrical connectors. The restraint system diagnostic tools must be removed prior to operating the vehicle over the road.

NOTE: After diagnosing or repairing an SRS, the restraint system diagnostic tools must be removed before operating the vehicle over the road.

NOTE: After diagnosing or repairing a seat system, the restraint system diagnostic tools must be removed before operating the vehicle over the road.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

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