Input Circuits - Hybrid Battery Current Measurement
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The BECM monitors current through the hybrid battery current sensor. The hybrid battery current sensor is mounted on the positive cable side internal to the hybrid drive motor generator battery assembly. The current sensor detects the amperage that flows in and out of the hybrid batteries. The current sensor inputs a voltage between 0-5 volts in proportion to the amperage. A reading of 2.5 volts is 0 amps.