Diagnostic Aids
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.
A single high voltage contactor relay stuck closed can set this DTC. If a high voltage contactor relay is closed when the BECM runs this test, the circuitry in the power inverter module will cause a loss of isolation to be detected.