B1870

Pinpoint Test 35: 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: 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: If 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 arid 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.

Step 1 - 2:

Step 3 - 5:

TEST DESCRIPTION