Circuit/System Description
WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The high voltage circuit impact detection (HVCID) sensor utilizes a unidirectional 2-wire circuit. The HVCID sensor modulates current on the circuit interface to send ID, state of health, and collision status to the serial data gateway (SDG) module. The SDG module serves as a power source and a ground for the HVCID sensor. When the ignition is turned ON and input power from the SDG module is first detected, the HVCID sensor responds by performing internal diagnostics and sending an ID to the SDG module. The HVCID sensor continually communicates status messages to the SDG module, which determines if a failure is present in the HVCID circuit.