Circuit/System Verification
WARNING: This page is about a different car, the 2008 Pontiac Torrent and 2008 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
Engine running, observe the scan tool ECM Ignition 1 signal parameter. The ignition 1 signal parameter should read between 11.5-15.5 volts.