B1870

Pinpoint Test 33: DTC B1870 - AIR BAG INDICATOR SHORTED TO BATTERY

Normal Operation
The air bag indicator is designed to illuminate for six (+/- two) seconds when the ignition switch is turned to the RUN position. This initial six seconds of illumination is considered normal operation and is called prove-out of the air bag indicator. The air bag indicator is then used to warn the driver that there is a fault in the air bag supplemental restraint system (SRS).

While the air bag indicator is activated, the restraints control module (RCM) monitors the air bag indicator for short to battery conditions. If the RCM detects a short to battery condition on the air bag indicator circuit, it will store a diagnostic trouble code (DTC) B1870 in memory. If the RCM detects an air bag indicator failure in addition to another SRS failure, the RCM will send a signal to the instrument cluster to produce five sets of five tone bursts.

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