Test R: DTC B1870 - Air Bag Indicator Short to Battery
R1 - R2
R2 - R3
R4
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 air bag Electronic Crash Sensor (ECS) module monitors the air bag indicator for short to battery conditions. If the ECS 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 ECS detects an air bag indicator failure in addition to another SRS failure, the ECS will send a signal to the Total Warning System (TWS) module to produce five sets of five tone bursts.
Possible Causes
An air bag indicator short to battery condition could be caused by:
