B1891

Pinpoint Test 36: DTC B1891 - Air Bag Tone Warning Indicator Circuit Shorted to Battery or Ignition

Normal Operation
The restraints control module (RCM) monitors its connection to the instrument cluster at C-220a, pin 16. This connection is used to signal a chime if the air bag indicator is inoperative and another SRS fault exists. If the RCM detects a short to battery or ignition on the connection to the instrument cluster, it will store a diagnostic trouble code (DTC) B1891 in memory.

Possible Causes
An air bag tone warning indicator circuit short to battery or ignition can be caused by:
- a short to battery or ignition on circuit (LB/B).
- a damaged or inoperative instrument cluster.
- a damaged RCM.

WARNING: The air bag diagnostic tool is for restraint system repair only. Remove from vehicle prior to road use. Failure to remove could result in injury and possible violation of vehicle safety standards

NOTE: It a seat equipped with a seat-mounted side air bag and/or a safety belt pretensioner (if equipped) system is being serviced, the air bag system must be deactivated using the appropriate deactivation procedure in this section.

NOTE: Restraint system diagnostic tools MUST be installed under the seats in the side air bag and safety belt pretensioner to floor connectors.

NOTE: Diagnostics or repairs are not to be performed on a side air bag system and/or a safety belt pretensioner (if equipped) system with the seats in the vehicle. Prior to attempting to diagnose/repair the side air bag system and/or safety belt pretensioner (if equipped) system the seats must be removed from the vehicle and the restraint system diagnostic tools must be installed in the side air bag and the safety belt pretensioner (if equipped) connectors at the floor connectors. The restraint system diagnostic tools must be removed prior to operating the vehicle over the road.

NOTE: Diagnostics may be performed on seat systems other than the side air bag or the safety belt pretensioner (if equipped) system (lumbar, climate controlled, heated, power seat track) with the seat installed in the vehicle as long as the restraint system diagnostic tools are installed under the seats in the side air bag and safety belt pretensioner to floor connectors.

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

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TEST DESCRIPTION