T: DTC B1870 - Air Bag Indicator Shorted to Battery

Normal Operation
The air bag indicator is designed to illuminate for 6 (±2) seconds when the ignition switch is turned to the RUN position. This initial 6 seconds of illumination is considered normal operation and is called proveout 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).

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 Generic Electronic Module (GEM) to produce five sets of five tone bursts.

Possible Causes
An air bag indicator short to battery condition could be caused by:
- damaged wiring on circuit 608 (BK/YE).
- an instrument cluster malfunction.
- an RCM internal concern.

Pinpoint Test Steps:

T1-T2:

T3-T4: