Circuit/System Description
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the current through the negative battery cable. It directly inputs to the body control module (BCM). It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz, and varies the duty cycle. The BCM supplies a 5-volt reference to the battery current sensor. If the BCM detects that the 5-volt reference circuit is shorted, then DTC B1405 sets.